Improve memory usage when checking for NaNs
Addition of pylearn2.utils.contains_inf and pylearn2.utils.isfinite
fix for issue 1057
Merge pull request #1060 from memimo/1057

fix for issue 1057
Merge pull request #1054 from madisonmay/nancheck

Improve memory usage when checking for NaNs
Fix izip usage in python3.

fix gh-1046 I guess there is other python 3 issue.
Update doc about izip
Merge pull request #1059 from nouiz/izip

Fix izip usage in python3.