Update mobilenetv2 symbol definition (#10595)
Update mobilenetv2 symbol definition (#10595)

* Update mobilenetv2 symbols

The pretrained model is provided in [this](https://github.com/liangfu/mxnet-mobilenet-v2) repository, where both model size and inference accuracy have been reproduced.

* update class and function names upon request

* remove camel cases in function naming

* bug fix in passing `multiplier` to `num_filter`

* update params_list

update params_list to be exactly described in the mobilenetv2 paper, which is published more recently in april.

sxjscience/mxnet,apache/incubator-mxnet,leezu/mxnet,ForkedReposBak/mxnet,yajiedesign/mxnet,yajiedesign/mxnet,fullfanta/mxnet,indhub/mxnet,jamesliu/mxnet,zhreshold/mxnet,larroy/mxnet,tlby/mxnet,leezu/mxnet,precedenceguo/mxnet,eric-haibin-lin/mxnet,navrasio/mxnet,jamesliu/mxnet,sxjscience/mxnet,navrasio/mxnet,ptrendx/mxnet,dmlc/mxnet,yajiedesign/mxnet,tlby/mxnet,mbaijal/incubator-mxnet,reminisce/mxnet,rahul003/mxnet,szha/mxnet,reminisce/mxnet,yajiedesign/mxnet,zhreshold/mxnet,ptrendx/mxnet,sxjscience/mxnet,tlby/mxnet,rahul003/mxnet,fullfanta/mxnet,zhreshold/mxnet,ForkedReposBak/mxnet,jamesliu/mxnet,zhreshold/mxnet,tlby/mxnet,reminisce/mxnet,eric-haibin-lin/mxnet,sxjscience/mxnet,jamesliu/mxnet,larroy/mxnet,jamesliu/mxnet,rahul003/mxnet,szha/mxnet,szha/mxnet,zhreshold/mxnet,dmlc/mxnet,ptrendx/mxnet,apache/incubator-mxnet,ForkedReposBak/mxnet,indhub/mxnet,mbaijal/incubator-mxnet,sxjscience/mxnet,sxjscience/mxnet,fullfanta/mxnet,larroy/mxnet,fullfanta/mxnet,jamesliu/mxnet,ptrendx/mxnet,navrasio/mxnet,reminisce/mxnet,indhub/mxnet,larroy/mxnet,ForkedReposBak/mxnet,ptrendx/mxnet,leezu/mxnet,mbaijal/incubator-mxnet,tlby/mxnet,fullfanta/mxnet,mbaijal/incubator-mxnet,yajiedesign/mxnet,szha/mxnet,leezu/mxnet,tlby/mxnet,szha/mxnet,eric-haibin-lin/mxnet,indhub/mxnet,precedenceguo/mxnet,navrasio/mxnet,reminisce/mxnet,apache/incubator-mxnet,eric-haibin-lin/mxnet,eric-haibin-lin/mxnet,indhub/mxnet,tlby/mxnet,rahul003/mxnet,rahul003/mxnet,jamesliu/mxnet,indhub/mxnet,szha/mxnet,ForkedReposBak/mxnet,ptrendx/mxnet,yajiedesign/mxnet,fullfanta/mxnet,yajiedesign/mxnet,sxjscience/mxnet,reminisce/mxnet,navrasio/mxnet,eric-haibin-lin/mxnet,zhreshold/mxnet,DickJC123/mxnet,leezu/mxnet,eric-haibin-lin/mxnet,precedenceguo/mxnet,DickJC123/mxnet,leezu/mxnet,zhreshold/mxnet,precedenceguo/mxnet,apache/incubator-mxnet,jamesliu/mxnet,larroy/mxnet,dmlc/mxnet,fullfanta/mxnet,leezu/mxnet,fullfanta/mxnet,DickJC123/mxnet,larroy/mxnet,rahul003/mxnet,dmlc/mxnet,precedenceguo/mxnet,ForkedReposBak/mxnet,larroy/mxnet,navrasio/mxnet,larroy/mxnet,reminisce/mxnet,fullfanta/mxnet,ptrendx/mxnet,precedenceguo/mxnet,dmlc/mxnet,dmlc/mxnet,mbaijal/incubator-mxnet,tlby/mxnet,reminisce/mxnet,ForkedReposBak/mxnet,rahul003/mxnet,ptrendx/mxnet,zhreshold/mxnet,tlby/mxnet,reminisce/mxnet,rahul003/mxnet,navrasio/mxnet,indhub/mxnet,zhreshold/mxnet,mbaijal/incubator-mxnet,precedenceguo/mxnet,indhub/mxnet,ptrendx/mxnet,indhub/mxnet,leezu/mxnet,sxjscience/mxnet,dmlc/mxnet,ForkedReposBak/mxnet,mbaijal/incubator-mxnet,precedenceguo/mxnet,szha/mxnet,dmlc/mxnet,mbaijal/incubator-mxnet,tlby/mxnet,eric-haibin-lin/mxnet,yajiedesign/mxnet,DickJC123/mxnet,leezu/mxnet,rahul003/mxnet,navrasio/mxnet,jamesliu/mxnet,sxjscience/mxnet,ptrendx/mxnet,reminisce/mxnet,navrasio/mxnet,eric-haibin-lin/mxnet,szha/mxnet,yajiedesign/mxnet,szha/mxnet,larroy/mxnet,dmlc/mxnet,mbaijal/incubator-mxnet,ForkedReposBak/mxnet,precedenceguo/mxnet