Skip test when no c++ compiler

[BUG,DOC] Doc MILA status about Theano and don't review a view.

[BUG] fix UnravelIndex in corner cases where it returned a view without declaring it. A test fail in the daily buidlbot.

small simplification

Buildbot: exclude MPI tests that cannot complete

Disallow float16 precision for convolution gradients functions.

Use the right mask to check for alignement.

Make setup.py fallback when versioneer can't get the version.

ARange gradient (contd)

Upsamp2

correct gradient for ARange

Fixup by using the good num_step used and using DisconnectedType instead of zeros (This change what was requested), remove +1. Test another corner case.

Fix opt crash and crash/tests when SciPy is not there.

Try to fix test_mpi_roundtrip tests not finising. Use Popen.communicate as it can prevent OS deadlock from Python doc.