add SpatialWithinChannelLRN, update the mapping of caffe lrn (#1364)
add SpatialWithinChannelLRN, update the mapping of caffe lrn (#1364)

* add SpatialWithinChannelLRN

* add python

* fix map error

* fix python

* meet code review

* update doc

intel-analytics/BigDL,intel-analytics/BigDL,intel-analytics/BigDL,yangw1234/BigDL,intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL,yangw1234/BigDL