typo, close bug #2358133
Fixed histogram autoscaling bug when bins or range are given explicitly
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
