Fixed check of the existence of the cuda_ndarray module under Windows, where the extension is not .so

Allow the default value of parameter dx,dy of ConvOp.__init__. They are set explicitly to 1 by the conv() fct.

remove FAST_RUN_NOGC from the acceptable value of flag mode. People should use the flag linker=c|py_nogc

In a test, test that we generate an error only when one is needed and test the type of the error generated.

In sparse.CSMProperties, don't put the last return as view, as we create a new ndarray from a tuple.

make debugmode use the new theano.misc.may_share_memory.may_share_memory fct to don't raise useless warning. It was calling the wrong *Type.may_share_memory sometimes.

added new theano.misc.may_share_memory that handle more case and can be called in all case(with and without scipy,...). Test it.