Use less aggressive garbage collection. Fixes GH-3044.
Small changes to clean up webagg javascript code a bit.
Added the nbAgg backend to allow interactive figures in the IPython
notebook.
Updates to make behaviour more consistent with other backends. Removed the throttling.
Improves description the return value from plt.hist()
Improves docs to be more like numpydoc
Formats return values as suggested
Removes extra space and space on line endings
Updates return description
Improves parameter description and how return maps to input
BUG : patches.Wedge.set_radius set wrong attribute

set_radius set the attribute `radius` which is not
used to compute the path.  Change to set `self.r` which
is used.
BUG : turned clipping off on pie chart components
 - set default value of `clip_on` in *prop dicts
 - closes #2518
BUG/API : tweaked how AnchoredSizeBar handles font properties

 - removed the explicit `prop` from
    `mpl_toolkits.axes_grid1.anchored_artists.AnchoredSizeBar`
 - pass `fontproperties` through to the base class in place of `prop`
 - if `prop` is not None and `fontproperties` is None, then use
   `prop` in place of `fontproperties`.
BLD : fix build on windows

patch suggested by cgohlke to fix issues with building
FreeType extension

Closes #3140
cleaned up rouge merge lines
first commit
python3 shebang
figures
user guide structure
mouse tracking tutorial for glade and some more changes