Fix redundancy of parameter backward computation
Fix redundancy of parameter backward computation

wangg12/caffe,longjon/caffe,tackgeun/caffe,gogartom/caffe-textmaps,gnina/gnina,gnina/gnina,gnina/gnina,CZCV/s-dilation-caffe,CZCV/s-dilation-caffe,tackgeun/caffe,gogartom/caffe-textmaps,wangg12/caffe,tackgeun/caffe,wangg12/caffe,CZCV/s-dilation-caffe,tackgeun/caffe,gnina/gnina,longjon/caffe,longjon/caffe,CZCV/s-dilation-caffe,gogartom/caffe-textmaps,gogartom/caffe-textmaps,wangg12/caffe,gnina/gnina,gnina/gnina,longjon/caffe