Accuracy Function For Speeding Up LSTM+CTC Convergence (#4865)
Accuracy Function For Speeding Up LSTM+CTC Convergence (#4865)

* Accuracy Function For Speeding Up Convergence

When processing Sequence Tagging problems, an accuracy func which is too strict is not convergence-friendly.
This accuracy function is from the solution of a basic leetcode problem LCS (Largest Common Subsequence).
Original All-Correct-Or-Nothing accuracy function may takes 7x times (or more) long to achieve certain accuracy.

* Another commit after CI fixed

Another commit after CI fixed

kevinthesun/mxnet,sergeykolychev/mxnet,hotpxl/mxnet,fullfanta/mxnet,madjam/mxnet,vikingMei/mxnet,piiswrong/mxnet,nicklhy/mxnet,szha/mxnet,rishita/mxnet,apache/incubator-mxnet,reminisce/mxnet,fullfanta/mxnet,gautamkmr/incubator-mxnet,Prasad9/incubator-mxnet,jamesliu/mxnet,coder-james/mxnet,EvanzzzZ/mxnet,xcgoner/dist-mxnet,ShownX/incubator-mxnet,jiajiechen/mxnet,ShownX/incubator-mxnet,ZihengJiang/mxnet,EvanzzzZ/mxnet,arank/mxnet,likelyzhao/mxnet,ShownX/incubator-mxnet,rahul003/mxnet,pluskid/mxnet,ZihengJiang/mxnet,LinkHS/incubator-mxnet,hotpxl/mxnet,ptrendx/mxnet,ptrendx/mxnet,precedenceguo/mxnet,Mega-DatA-Lab/mxnet,precedenceguo/mxnet,LinkHS/incubator-mxnet,jennyzhang0215/incubator-mxnet,larroy/mxnet,saurabh3949/mxnet,dmlc/mxnet,LinkHS/incubator-mxnet,luoyetx/mxnet,TuSimple/mxnet,eric-haibin-lin/mxnet,gautamkmr/incubator-mxnet,navrasio/mxnet,formath/mxnet,thirdwing/mxnet,gautamkmr/incubator-mxnet,Mega-DatA-Lab/mxnet,DR08/mxnet,nicklhy/mxnet,DickJC123/mxnet,wangyum/mxnet,arikpoz/mxnet,CodingCat/mxnet,hesseltuinhof/mxnet,EvanzzzZ/mxnet,kkk669/mxnet,formath/mxnet,sergeykolychev/mxnet,LinkHS/incubator-mxnet,eric-haibin-lin/mxnet,yuruofeifei/mxnet,kkk669/mxnet,ZihengJiang/mxnet,pluskid/mxnet,kevinthesun/mxnet,rishita/mxnet,Northrend/mxnet,eric-haibin-lin/mxnet,jamesliu/mxnet,leezu/mxnet,leezu/mxnet,yajiedesign/mxnet,coder-james/mxnet,solin319/incubator-mxnet,arikpoz/mxnet,pluskid/mxnet,jermainewang/mxnet,solin319/incubator-mxnet,smolix/incubator-mxnet,nicklhy/mxnet,apache/incubator-mxnet,hotpxl/mxnet,Ldpe2G/mxnet,ForkedReposBak/mxnet,DickJC123/mxnet,rahul003/mxnet,hotpxl/mxnet,tornadomeet/mxnet,weleen/mxnet,Mega-DatA-Lab/mxnet,sxjscience/mxnet,jamesliu/mxnet,rahul003/mxnet,szha/mxnet,weleen/mxnet,sergeykolychev/mxnet,precedenceguo/mxnet,apaleyes/mxnet,tlby/mxnet,EvanzzzZ/mxnet,kevinthesun/mxnet,indhub/mxnet,luoyetx/mxnet,solin319/incubator-mxnet,leezu/mxnet,dmlc/mxnet,Ldpe2G/mxnet,gautamkmr/incubator-mxnet,jennyzhang0215/incubator-mxnet,Prasad9/incubator-mxnet,Prasad9/incubator-mxnet,Ldpe2G/mxnet,danithaca/mxnet,crazy-cat/incubator-mxnet,CodingCat/mxnet,thirdwing/mxnet,hotpxl/mxnet,reminisce/mxnet,tornadomeet/mxnet,Prasad9/incubator-mxnet,Prasad9/incubator-mxnet,madjam/mxnet,vikingMei/mxnet,kevinthesun/mxnet,leezu/mxnet,vikingMei/mxnet,sergeykolychev/mxnet,sergeykolychev/mxnet,dmlc/mxnet,jermainewang/mxnet,kevinthesun/mxnet,saurabh3949/mxnet,DR08/mxnet,wangyum/mxnet,hpi-xnor/BMXNet,jennyzhang0215/incubator-mxnet,jennyzhang0215/incubator-mxnet,ykim362/mxnet,likelyzhao/mxnet,ZihengJiang/mxnet,tlby/mxnet,fullfanta/mxnet,Northrend/mxnet,madjam/mxnet,jermainewang/mxnet,thirdwing/mxnet,crazy-cat/incubator-mxnet,crazy-cat/incubator-mxnet,Prasad9/incubator-mxnet,coder-james/mxnet,DR08/mxnet,fullfanta/mxnet,ForkedReposBak/mxnet,jamesliu/mxnet,sergeykolychev/mxnet,tlby/mxnet,Northrend/mxnet,precedenceguo/mxnet,antoan2/incubator-mxnet,eric-haibin-lin/mxnet,szha/mxnet,leezu/mxnet,precedenceguo/mxnet,saurabh3949/mxnet,arikpoz/mxnet,likelyzhao/mxnet,piiswrong/mxnet,mbaijal/incubator-mxnet,jermainewang/mxnet,gautamkmr/incubator-mxnet,piiswrong/mxnet,madjam/mxnet,piiswrong/mxnet,madjam/mxnet,zhreshold/mxnet,navrasio/mxnet,luoyetx/mxnet,formath/mxnet,nicklhy/mxnet,kevinthesun/mxnet,smolix/incubator-mxnet,luoyetx/mxnet,ykim362/mxnet,TuSimple/mxnet,stefanhenneking/mxnet,xcgoner/dist-mxnet,xcgoner/dist-mxnet,ForkedReposBak/mxnet,smolix/incubator-mxnet,luoyetx/mxnet,hpi-xnor/BMXNet,tornadomeet/mxnet,fullfanta/mxnet,zhreshold/mxnet,DR08/mxnet,ykim362/mxnet,tlby/mxnet,yajiedesign/mxnet,antoan2/incubator-mxnet,hpi-xnor/BMXNet,jamesliu/mxnet,rishita/mxnet,antoan2/incubator-mxnet,jiajiechen/mxnet,jiajiechen/mxnet,DR08/mxnet,crazy-cat/incubator-mxnet,eric-haibin-lin/mxnet,indhub/mxnet,luoyetx/mxnet,tlby/mxnet,fullfanta/mxnet,CodingCat/mxnet,rishita/mxnet,arank/mxnet,luoyetx/mxnet,reminisce/mxnet,danithaca/mxnet,mbaijal/incubator-mxnet,navrasio/mxnet,zhreshold/mxnet,dmlc/mxnet,danithaca/mxnet,DR08/mxnet,yuruofeifei/mxnet,vikingMei/mxnet,pluskid/mxnet,sxjscience/mxnet,wangyum/mxnet,wangyum/mxnet,solin319/incubator-mxnet,lxn2/mxnet,ZihengJiang/mxnet,szha/mxnet,ykim362/mxnet,danithaca/mxnet,coder-james/mxnet,EvanzzzZ/mxnet,coder-james/mxnet,szha/mxnet,likelyzhao/mxnet,sergeykolychev/mxnet,ForkedReposBak/mxnet,TuSimple/mxnet,ykim362/mxnet,jermainewang/mxnet,arikpoz/mxnet,eric-haibin-lin/mxnet,kkk669/mxnet,formath/mxnet,lxn2/mxnet,xcgoner/dist-mxnet,Northrend/mxnet,TuSimple/mxnet,ForkedReposBak/mxnet,saurabh3949/mxnet,mbaijal/incubator-mxnet,tornadomeet/mxnet,stefanhenneking/mxnet,reminisce/mxnet,xcgoner/dist-mxnet,coder-james/mxnet,hesseltuinhof/mxnet,apaleyes/mxnet,CodingCat/mxnet,ShownX/incubator-mxnet,likelyzhao/mxnet,LinkHS/incubator-mxnet,jennyzhang0215/incubator-mxnet,nicklhy/mxnet,dmlc/mxnet,arikpoz/mxnet,mbaijal/incubator-mxnet,mbaijal/incubator-mxnet,Mega-DatA-Lab/mxnet,kkk669/mxnet,kkk669/mxnet,yajiedesign/mxnet,szha/mxnet,navrasio/mxnet,navrasio/mxnet,Mega-DatA-Lab/mxnet,yuruofeifei/mxnet,Prasad9/incubator-mxnet,CodingCat/mxnet,tornadomeet/mxnet,fullfanta/mxnet,arank/mxnet,smolix/incubator-mxnet,arank/mxnet,Ldpe2G/mxnet,dmlc/mxnet,larroy/mxnet,danithaca/mxnet,hesseltuinhof/mxnet,hotpxl/mxnet,nicklhy/mxnet,fullfanta/mxnet,jennyzhang0215/incubator-mxnet,yajiedesign/mxnet,ShownX/incubator-mxnet,larroy/mxnet,tornadomeet/mxnet,EvanzzzZ/mxnet,xcgoner/dist-mxnet,stefanhenneking/mxnet,LinkHS/incubator-mxnet,reminisce/mxnet,danithaca/mxnet,kevinthesun/mxnet,precedenceguo/mxnet,gautamkmr/incubator-mxnet,crazy-cat/incubator-mxnet,saurabh3949/mxnet,lxn2/mxnet,zhreshold/mxnet,formath/mxnet,zhreshold/mxnet,apaleyes/mxnet,formath/mxnet,rahul003/mxnet,larroy/mxnet,madjam/mxnet,danithaca/mxnet,pluskid/mxnet,wangyum/mxnet,weleen/mxnet,yajiedesign/mxnet,kevinthesun/mxnet,vikingMei/mxnet,larroy/mxnet,coder-james/mxnet,wangyum/mxnet,ptrendx/mxnet,likelyzhao/mxnet,indhub/mxnet,pluskid/mxnet,apaleyes/mxnet,yuruofeifei/mxnet,Northrend/mxnet,pluskid/mxnet,precedenceguo/mxnet,hesseltuinhof/mxnet,Ldpe2G/mxnet,madjam/mxnet,crazy-cat/incubator-mxnet,sxjscience/mxnet,Northrend/mxnet,DickJC123/mxnet,sxjscience/mxnet,jamesliu/mxnet,likelyzhao/mxnet,thirdwing/mxnet,fullfanta/mxnet,hotpxl/mxnet,tlby/mxnet,mbaijal/incubator-mxnet,ForkedReposBak/mxnet,thirdwing/mxnet,Ldpe2G/mxnet,LinkHS/incubator-mxnet,arikpoz/mxnet,hotpxl/mxnet,dmlc/mxnet,hesseltuinhof/mxnet,arank/mxnet,precedenceguo/mxnet,jennyzhang0215/incubator-mxnet,vikingMei/mxnet,rishita/mxnet,yuruofeifei/mxnet,nicklhy/mxnet,indhub/mxnet,rahul003/mxnet,piiswrong/mxnet,ZihengJiang/mxnet,ykim362/mxnet,DR08/mxnet,apache/incubator-mxnet,solin319/incubator-mxnet,weleen/mxnet,gautamkmr/incubator-mxnet,Prasad9/incubator-mxnet,yajiedesign/mxnet,lxn2/mxnet,DR08/mxnet,kkk669/mxnet,larroy/mxnet,kkk669/mxnet,jiajiechen/mxnet,madjam/mxnet,tlby/mxnet,tornadomeet/mxnet,formath/mxnet,jiajiechen/mxnet,Mega-DatA-Lab/mxnet,arikpoz/mxnet,sxjscience/mxnet,antoan2/incubator-mxnet,luoyetx/mxnet,madjam/mxnet,stefanhenneking/mxnet,navrasio/mxnet,solin319/incubator-mxnet,saurabh3949/mxnet,ptrendx/mxnet,xcgoner/dist-mxnet,indhub/mxnet,TuSimple/mxnet,jiajiechen/mxnet,saurabh3949/mxnet,stefanhenneking/mxnet,lxn2/mxnet,hesseltuinhof/mxnet,zhreshold/mxnet,weleen/mxnet,solin319/incubator-mxnet,danithaca/mxnet,Mega-DatA-Lab/mxnet,TuSimple/mxnet,tlby/mxnet,reminisce/mxnet,mbaijal/incubator-mxnet,thirdwing/mxnet,szha/mxnet,LinkHS/incubator-mxnet,szha/mxnet,lxn2/mxnet,xcgoner/dist-mxnet,stefanhenneking/mxnet,CodingCat/mxnet,stefanhenneking/mxnet,jamesliu/mxnet,solin319/incubator-mxnet,hpi-xnor/BMXNet,dmlc/mxnet,piiswrong/mxnet,piiswrong/mxnet,ShownX/incubator-mxnet,saurabh3949/mxnet,navrasio/mxnet,yajiedesign/mxnet,Mega-DatA-Lab/mxnet,TuSimple/mxnet,indhub/mxnet,piiswrong/mxnet,yuruofeifei/mxnet,nicklhy/mxnet,sxjscience/mxnet,yuruofeifei/mxnet,crazy-cat/incubator-mxnet,hesseltuinhof/mxnet,yuruofeifei/mxnet,indhub/mxnet,arikpoz/mxnet,indhub/mxnet,ptrendx/mxnet,xcgoner/dist-mxnet,ZihengJiang/mxnet,ShownX/incubator-mxnet,lxn2/mxnet,mbaijal/incubator-mxnet,gautamkmr/incubator-mxnet,ptrendx/mxnet,ptrendx/mxnet,likelyzhao/mxnet,rishita/mxnet,rishita/mxnet,formath/mxnet,formath/mxnet,sergeykolychev/mxnet,vikingMei/mxnet,leezu/mxnet,ForkedReposBak/mxnet,Prasad9/incubator-mxnet,jiajiechen/mxnet,jiajiechen/mxnet,jamesliu/mxnet,lxn2/mxnet,DR08/mxnet,vikingMei/mxnet,TuSimple/mxnet,eric-haibin-lin/mxnet,larroy/mxnet,wangyum/mxnet,Northrend/mxnet,smolix/incubator-mxnet,ZihengJiang/mxnet,ForkedReposBak/mxnet,arank/mxnet,szha/mxnet,yajiedesign/mxnet,CodingCat/mxnet,apaleyes/mxnet,Ldpe2G/mxnet,arank/mxnet,thirdwing/mxnet,nicklhy/mxnet,rishita/mxnet,zhreshold/mxnet,ptrendx/mxnet,tlby/mxnet,vikingMei/mxnet,weleen/mxnet,crazy-cat/incubator-mxnet,pluskid/mxnet,solin319/incubator-mxnet,EvanzzzZ/mxnet,smolix/incubator-mxnet,kkk669/mxnet,smolix/incubator-mxnet,antoan2/incubator-mxnet,wangyum/mxnet,ShownX/incubator-mxnet,TuSimple/mxnet,rahul003/mxnet,arikpoz/mxnet,hpi-xnor/BMXNet,Northrend/mxnet,stefanhenneking/mxnet,hpi-xnor/BMXNet,weleen/mxnet,larroy/mxnet,pluskid/mxnet,ykim362/mxnet,rahul003/mxnet,reminisce/mxnet,kevinthesun/mxnet,LinkHS/incubator-mxnet,ykim362/mxnet,eric-haibin-lin/mxnet,jennyzhang0215/incubator-mxnet,reminisce/mxnet,Ldpe2G/mxnet,antoan2/incubator-mxnet,CodingCat/mxnet,ykim362/mxnet,tornadomeet/mxnet,ptrendx/mxnet,hpi-xnor/BMXNet,rahul003/mxnet,hotpxl/mxnet,zhreshold/mxnet,leezu/mxnet,jiajiechen/mxnet,leezu/mxnet,apaleyes/mxnet,Northrend/mxnet,apaleyes/mxnet,sxjscience/mxnet,weleen/mxnet,TuSimple/mxnet,navrasio/mxnet,coder-james/mxnet,mbaijal/incubator-mxnet,luoyetx/mxnet,hpi-xnor/BMXNet,tornadomeet/mxnet,CodingCat/mxnet,antoan2/incubator-mxnet,saurabh3949/mxnet,arank/mxnet,thirdwing/mxnet,Ldpe2G/mxnet,leezu/mxnet,rahul003/mxnet,navrasio/mxnet,crazy-cat/incubator-mxnet,apaleyes/mxnet,precedenceguo/mxnet,eric-haibin-lin/mxnet,hesseltuinhof/mxnet,smolix/incubator-mxnet,sxjscience/mxnet,jennyzhang0215/incubator-mxnet,ShownX/incubator-mxnet,likelyzhao/mxnet,weleen/mxnet,indhub/mxnet,jermainewang/mxnet,ptrendx/mxnet,jermainewang/mxnet,danithaca/mxnet,stefanhenneking/mxnet,jamesliu/mxnet,DickJC123/mxnet,jermainewang/mxnet,EvanzzzZ/mxnet,antoan2/incubator-mxnet,larroy/mxnet,EvanzzzZ/mxnet,reminisce/mxnet,gautamkmr/incubator-mxnet,rishita/mxnet,smolix/incubator-mxnet,tlby/mxnet,sxjscience/mxnet,piiswrong/mxnet,antoan2/incubator-mxnet,hpi-xnor/BMXNet,wangyum/mxnet,apache/incubator-mxnet,reminisce/mxnet,dmlc/mxnet,arank/mxnet,yajiedesign/mxnet,hesseltuinhof/mxnet,kkk669/mxnet,ZihengJiang/mxnet,zhreshold/mxnet,yuruofeifei/mxnet,sergeykolychev/mxnet,apaleyes/mxnet,ForkedReposBak/mxnet,coder-james/mxnet,lxn2/mxnet,jermainewang/mxnet,Mega-DatA-Lab/mxnet,thirdwing/mxnet