update doc for retina functionality
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Changed ModelMethodPenalty to MethodCost
Changed ExhaustiveSGD to SGD and EpochCounter module's root
Merge remote-tracking branch 'upstream/master' into autoencoder_scripts
fixed typo
Merge remote-tracking branch 'upstream/master' into autoencoder_scripts
Merge pull request #557 from bouthilx/autoencoder_scripts

Fix Autoencoder yaml files
put citation in same format as it appears in a latex rendered article
fixed other sphinx warnings
Merge pull request #549 from goodfeli/doc_retina

update doc for retina functionality
use Pillow in travis-ci tests.
Merge pull request #567 from nouiz/pillow

use Pillow in travis-ci tests.
Merge pull request #551 from goodfeli/userpath

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