axes.py: Shorten source code lines so all are less than 80 chars long.
added support for leave_notify_event in backend_qt4
Make scale colors match line colors in two_scales.py
fixed leave_notify_event for gtk -- need support for other UIs
added figure/axes enter/leave events
added rc param axes.unicode_minus
added a chance for polar with usetex to remove unicode symbol
removed comment from invalid shared axis merge
Remove code that was inadvertently merged from branch.
