minfx SVN archive

From numpy version 1.9, the FutureWarning "__main__:1: FutureWarning: comparison to `None` will
result in an elementwise object comparison in the future." is seen in a number of minfx's
optimisation algorithms, and in all of the constraint algorithms.

The issue is that the behaviour of the comparison operators '==' and '!=' will change with future
numpy versions. These have been replaced with 'is' and 'is not' throughout.