added show_negative_chains
Merge pull request #137 from goodfeli/master

Fix dtype bug that was making travis tests fail
added a TODO
more monitoring channels
sparsely connected units
visualization stuff
Merge branch 'master' of github.com:lisa-lab/pylearn
New log_timing context manager.
First pass at moving to loggers.

Most things are at INFO log-level. By default the formatting is
configured by the train script to look like regular print statements.

Also moved several pieces of timing code over to the log_timing system.
added a monitoring channel
made batch_gradient_descent default to using min_init_alpha of .001
made BGD use min_init_alpha of .001 by default
Merge branch 'master' of github.com:lisa-lab/pylearn
made probabilistic max pooling use sigmoid instead of a big graph when
possible
added a todo
added external tests when available
sped up a test
mport cleanuip
added mean field InferenceProcedure
added init_mf_state