Add optimizer merging two switches of same condition

[MRG] UnicodeDecodeError exceptions due to accents

Fix problem with python 3.5.

Add graph optimization 0/x -> 0

It would raise a SystemError wrapping the IndexError already raised.

Add flag: profiling.ignore_first_call and Update How To release.

Fix compilation on mac with CLT 7.3

Better error message

Fixes grammatical errors in theano.nnet.softmax doc

Decoding nvcc outputs in correct encoding.

Clarified graphviz dependency

Repair the -rpath linker option in Windows System

Fixes for debugmode in dnn and gpuarray

(nit) tutorial typos

Fix tests in DebugMode with DNN convolutions

Add the same restriction to the perform to return the same error and …

Add the same restriction to the perform to return the same error and have test don't use more then 9G of RAM.

Fix windows test failures

(nit) sparse tutorial typos