Use less aggressive garbage collection. Fixes GH-3044.
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
BLD : made tornado an optional external package

closes #3039
DOC : documented bottom kwarg of hist

closes #3136
DOC : changes to histogram Returns doc section

 - minor wording changes
 - pep8 cleanup
Merge branch 'improving-plt.hist-documentation'
Update pyplot_tutorial.rst

Fixed minor typo in "Using mathematical expressions in text". "...not to treat backslashes and python escapes." changed to "...as python escapes."
DOC : add prominent doc about set_useOffset

added text to both ticker.py and FAQ

closes #2796
Merge pull request #3169 from otepoti/master

Update pyplot_tutorial.rst
Merge pull request #3162 from tacaswell/tornado_noreq

BLD : made tornado an optional external package