Log Message:

	0.4 (2013-12-17)
----------------

- Introduced Contexts: relation between incompatible dimensions.
  (Issue #65)
- Fixed get_base_units for non multiplicative units.
  (Related to issue #66)
- Implemented default formatting for quantities.
- Changed comparison between Quantities containing NumPy arrays.
  (Issue #75) - BACKWARDS INCOMPATIBLE CHANGE
- Fixes for NumPy 1.8 due to changes in handling binary ops.
  (Issue #73)