Implemented unittests which test that the contract for In is respected: we test
that aliasing the input is impossible with borrow=False.

Old theano versioning system is deprecated with DWF's latest changes. Versioning
is now handled through setup.py and mercurial hooks.

borrow argument for In, gradient of a mtrix ..)

are tested.

Fixes compatibility issues with MacHG and probably GUIs. (Note that the released version of MacHG actually doesn't work at the moment, but new ones should soon -- cf. http://bitbucket.org/jfh/machg/issue/141/p2d2-environment-variables-not-set)

Be a bit more liberal in what we accept for a join operation. No longer force all broadcastable flags for non-join axes to be the same, and the output's broadcastable flags are the OR of the input's for each axis.

Make SparseVariable test of Theano memory contract use the generic test fct. This make it test more case. I needed to change to idiv as implace op as scipy sparce support only idiv as inplace op.