Ready to merge: Determinism 2

Corrected the fully qualified name of RandomState class

places in docstrings.  It was spelled numpy.RandomState instead of
numpy.random.RandomState.

Fix EighGrad that didn't returned the good dtype when the input is float...

Use the real dtype in case of mixed dtype input and work around dtype change depending of numpy version.

This was an error in the buildbot.

Minor fixes (typos)

Fixed a few typos in documentation.

Added allow_gc Theano flags in the list of Theano flags.