Merge pull request #1 from nouiz/shackenberg-adding_GpuJoin.c_code

Fix error reporting
addeed GpuJoin.c_code_cache_version
doc: fix typo
Merge pull request #1483 from micklat/master

doc: fix typo
Add space for pep8 in documentation
Merge pull request #1469 from shackenberg/adding_GpuJoin.c_code

[WIP] Adding GpuJoin.c_code to cuda/basic_ops.py
Use the same reason as the tag of the optimization.

This allow to easily know how to disable that specific optimization.
Don't use an wrapper optimization when it is not needed.

This make the printing of the reason be simpler/more readable.
Add opt tag with the name of the opt for scan opt.

That allow to know easily witch tag to use to disable an opt.
pep8
pep8
Interface change. env feature on_prune() fct now take a reason parameter
Interface change: add param reason to env_reafure.on_import().
Add opt tag the reason used.
Do not call as_tensor_variable on other Theano variable.
typo in error message.
Add Theano flag compute_test_value_opt.
Use op.__call__() instead of op.make_node() to have test value inserted during opt.
Add test value during opt.
Fix typo in comments/error messages.