Add a mode to docgen to run the code samples in the documentation.

This alleviates copying them elsewhere to ensure they are not broken.
Add documenation to some dnn functions and make the file importable without a GPU.
Add mention that dnn_conv can be used manually since it has a gradient.
dnn_conv() documentation fixup after comments.
Define 'bc01'.
Merge pull request #2145 from abergeron/dnn_conv_doc

Dnn conv doc
Merge pull request #2078 from abergeron/doc

Add a mode to docgen to run the code samples in the documentation.
Fix test in fast_compile
fix test in FAST_COMPILE mode.
Fix test in FAST_COMPILE mode
pep8
Merge pull request #2164 from nouiz/tests

Fix buildbot errors.
Add pseudo-math in the docstring for GemvSS and OuterSS.
Merge pull request #2167 from abergeron/blocksparse_doc

Add pseudo-math in the docstring for GemvSS and OuterSS.
Closes #2141