added the python script and increase the robustness of the KL methods
update the python script
kde added
dual distance methods added;minor changes
Merge pull request #2388 from khalednasr/autoencoders

Implemented deep belief nets
Merge pull request #2386 from yorkerlin/develop

added the python script for KL methods
Merge pull request #2383 from mazumdarparijat/kdensity

kde added
Added neural layers builder (with test and python example)
added a notebook for autoencoders