Local subtensor of alloc

NEWS.txt
- Fix opt warning about local_subtensor_of_alloc related to input of alloc that is broadcastable (Frederic B., reported by Ira Korshunova)
- Fix broadcastable pattern when the input of Alloc was broadcastable and we take a slice that is empty (Frederic B.)

A few other minor stuff that aren't work mentioning:
- debugprint() now work on int, long, float, numpy.ndarray