Add locallyconnected2d layer (#2037)
Add locallyconnected2d layer (#2037)

* finish locallyconnected2d

* add locallyconnected2d

* add serializer test

* fix python test failed

* meet code review

* change spaticalConvolutionSpec

* remove a test

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