Added tests of some assumptions made on Numpy

Explain better why override some options in tests

Also some minor cosmetic changes to output.

Force the wanted device and floatX in the buildbot script.

Fix failing tests in tensor module

Doc str

A few small fixes

Elemwise should return both c_support_code and c_support_code_apply for the
scalar_op. It now does this and there is a comment explaining why.

Otherwise it may confuse users as nothing is printed to screen when it works.

In the shape feature, return to the old priority when we update the shape

Fix the enabling of gpu optimization.

Smallfix

add missing parenthesis that cause syntax error.

Made error message more explicit