Allow Python long int where int is expected.

Also allow numpy.integer, in case things like np.int64(...) are used.
When (int, float) were expected, allow numpy.number instead of
numpy.integer, so things like numpy.float32(...) also work.
Define groups of Python numeric types in utils
Fix call to numpy in theano_linear.
Merge pull request #198 from lamblin/allow_long

Allow Python long int where int is expected.