Fixed typo in doc of categorical cross-entropy

The true and coding distributions had been switched.
Also: a few PEP8 improvements.

CGemv now uses vector-vector dot product when appropriate

Doc

Infer shape broadcast

Needed for the ShapeFeature in later commit.

This solves a problem uncovered by the previous commit: a variable with
an ndim field could be replaced by a Variable without one.

dimensions that are broadcastable.

Also, a small modif to make those assert always work. Add a test for this.

This caused a crahs in the optimizer, as in one case, we didn't know
the shape was broadcastable by that path.

Cast indices to intp rather than intc.

The intent was correctly described in the comment - to cast to int32 on 32-bit machines and to int64
on 64-bit.  However, numpy.intc is not correct type to achieve that because it has the size of C int and
is 32-bit always.  The correct type is numpy.intp which is defined as "large enough to fit a pointer."

See http://docs.scipy.org/doc/numpy/reference/arrays.scalars.html .

Make compile_str able to compile a lib that is not a Python module

Added a verbosity flag to device_malloc.

Fix cachelock

Set the file in the compiledir, not the case. Some user set the compiledir directly, not the base_compiledir and this make that sometimes, the base_compiledir isn't working.

It is a todo to find a better fix, but to don't cause probleme, here is a work around.

Shorter error

Minor fixes