Python 3 support for Numba

This pull request add Python 3 support for Numba. Most tests are passed in Python 3, without compromising Python 2.7

90 Tests in total. (Skip: 1. Theano not installed)
Python 2.7: 0 Fail. 1 Skip. 89 Pass
Python 3.2: 8 Fail. 1 Skip. 81 Pass

For more information, see the discussion thread:
https://groups.google.com/a/continuum.io/forum/?fromgroups=#!topic/numba-users/YzJdvfs61CE