Change type of config.unittests.rseed so it accepts the value "random", as THEANO_UNITTEST_SEED did.

* removed numpy as N, tensor as T
* wrapped docstrings to 80cols
* moved getFilterOutShp to staticmethod
* removed some useless code (old convolve2 function)

Reimplemented unittests for conv.

Speed tests will go in separate file (to come)

-side effect, the cuda test are not enabled by default, will be on the build bot.
-also, now the use fct don't have a default value.

lower profiler overhead by moving computation into the printing phase instead of the recording phase.

Usefull to track the overhead of theano fct call.