Split tests and code for these ops.
Move the tests to tests/test_extra_ops.py.
Create extra_ops/__init__.py

Fix tests

Looks ok to me.

Pycuda init

This is probably due to wrong handling of context. I think theano and
pycuda don't use the same context while the should. I am investigating
the problem, but while this make the buildbot segfault, I disable it
for now.

Update to sparse sandbox

better error msg.

Mixed

Now test correctly what should not work as the functionality was implemented by PL.

Mixed