created model_extensions module
Added model_extension.py
add interface for censoring updates with extensions
remove use of deprecated interface
type checking
MLP __init__ callthrough
change MLP stuff to use new interface
fix stack level of warning
fix call to deprecated method
docstring
pep8 fixes
make all library code use modify_updates instead of censor_updates,
cleanup
Merge pull request #867 from goodfeli/master

Model extensions framework with interface for constrained optimization