Python fprop compatibility.
enhance examples
Merge pull request #17 from avdmitry/enhance_examples

enhance examples
GEMM kernels, support for rectangular kernels and images, minor edits.
Test for GEMM conv kernels.
Merge branch 'master' of https://github.com/TorontoDeepLearning/convnet
Update python fprop to use GEMM kernels.
Tests and fixes for cross map response norm.
Fixed range issue in ResponseNormUndo.
Added 3D convolution kernels.
fixed scaling bug in GEMM kernels.