Tutorial for C op

Minor fixes

[BUG] Fix TypeList missing view_map and fix crashes.

This cause the infershape to think the shape is one. This bad info can
be reused at many places.

This was done the 11 August in commit 94ec1975

It was merged the 12 August in gh-2029

TypeList.may_share_memory more resilent to different input type.

This was detected by a crash in DebugMode in the Theano buildbot as
another change made Type.may_share_memory obligatory in DebugMode. As
this discovered a bug, I'll keep this mandatory.

This fix a test in the buildbot.

Don't change the defaul log level during import. Otherwise, the user can...

Argparse is in Python 2.7. This file was added for compatibility with
older python.

We remove one of its user(nose_pr.py) that we don't use.

As we support python 2.6, I raise a good error message in the only
file that use it. As it is available in pypi, I think it is fine we
don't provide it for python 2.6, as this file isn't very important.

Don't change the defaul log level during import. Otherwise, the user can't get the log level he want during theano import.

fix gh-2130

Fix memory leak in scan related to the input and output storage of the inner function.

Fix blocksparse optimization that could give bad results in some cases

[ENH] Add SliceConstant, better stack trace, fast_compile_gpu