Added legend.framealpha to rcParams, as alluded to by axes.legend docstring
Added legend.framealpha line to template rcparam file
whats_new statement added
Move widget.{get,set}_active to AxisWidget.

The method was previously defined only for RectangleSelectors (#3375).

Also, an redundant line was removed (RectangleSelectors are already set
active on __init__ by the superclass).
Update background on widget.set_active(True).

Because selectors must update their background on set_active(True),
widget.active was made a property for backwards compatibility.
Updated whats_new.rst.

Because _Selector is a private class there are no references to the
actual getter and setter in the rst file.
Minor fixes according to Github discussion.
_SelectorWidget overrides the active property.

... so it should dynamically retrieve the set_active method.
Escape \ in math
Ignore file
Fix link to qt4 example
Fix links in tri docs, fixes warnings
Remove link to non existing color docs
Rewrite mlab doc. Fixes a warning
Rename internal links to avoid warning
Fix links in INSTALL

Conflicts:
	INSTALL
Fix link to no longer existing section
Make sure that labels are unique
Include type1font and dviread in api doc. Not included in any TOC before
Include patheffect guide in TOC