Add bilinear interpolation layer

* set mixedlayer output size according to input operator
* change from num_channel to num_channels for conv_operator (the old one is
really misleading because all the others are num_channels)

* also changed the arg name in projections.py

Fix matrix inverse  unittest to be more robust

rebase deconv implementation with develop branch and resolve conflicts with pull#218 commit 45c81a41

* the memory leak is inside one pass.

Update cluster_train.md for easier understanding

* some tiny fixs

* use VLOG(3)

* make AVX_FOUND is default value to WITH AVX
* let AVX_FLAG always keep -mavx flag since compiler can build binary with -mavx even CPU does not support avx.