TST: subtensor with float index raises TypeError

Adds regression test for bug fixed in https://github.com/Theano/Theano/pull/47

Fix pydotprint with ProfileMode

adding CURAND_RandomStreams with support for uniform and normal

Fix buildbot

basic indexing with floating point raises better error

incorrectly identified as advanced indexing

Mixed commit

Refactored _execute to make it more readable (using class instead of closure)

less likely to make incorrect assumptions while reading tracebacks

James added to AdvancedIncSubtensor1 the ability to do set intead of inc. But forgot to update the optimization to pass this new information.

This is a real bug introduced in the trunk but not released.

BUG: str -> basestring isinstance checks.

added a config variable to control the verbosity of exceptions

Add verbosity config

Add test for new fonctionality added by James.

review comments from @delallea
-moved previous developer-oriented description to code comments