SciTools/iris — pull request #472 by esc24 (2013-04-23 12:18:07+00:00)
Title: Modified logic in Unit.convert to handle numpy scalars.

This PR modifies the logic in ```iris.unit.Unit``` convert method so it can handle numpy scalar types such as np.int32.

This fixes #470 and should resolve #431 avoiding the need for workaround #471.