Merge pull request #442 from isolver/master

ENH: User defined font files can be added to the FontManager used by TextBox.
BF: removed mouse window exclusive on OSX

- already removed from other OS's. Since integration with psychopy there
is no reason iohub needs to have window related functionality that can
already be done in pyglet.
Merge branch 'master' of git://github.com/psychopy/psychopy