Added sparse initialization to AutoEncoder classes for weight matrices, along with corresponding changes to the SdA constructor that calls AutoEncoder constructors.
Changed the number of training epochs in both finetuning and pretraining
Merge branch 'dropout' of github.com:lzamparo/SdA_reduce into dropout

Conflicts:
	theano_models/SdA/SdA.py
	theano_models/SdA/finetune_SdA_multiproc.py