[IO] add back num_parts and part_index for imgrec
[IO] add back num_parts and part_index for imgrec

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