BUGFIX:  This change fixes #2475, where contour labels added manually
produce ugly spikes in the contours.  The problem was that screen
coordinates were being passed as data coordinates when the contour was
split to add room for the label.

Incorporate my fix and miili's #2806 change
TST : added test to exercise transform kwarg to `add_label_near`

This exercises with input in both display and data units.
Use less aggressive garbage collection. Fixes GH-3044.
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`.
BUG : fix fetch of freetype version during build

Use freetype-config --ftversion flag to get freetype version (previously
using freetype-config --version which returns libtool version).
DOC : added whats_new entry for Qt5 backend
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
restored default boxplot style and respect for the sym kwarg
fixed typos/formatting in docstrings
clean up whitespace
BUG : fix errors when using fliers

doplot for horizontal boxes (internal bxp helper function) assumes that
it will be passed an even number of positional arguments which it swaps
pair-wise.  The code to draw the fliers also passes in a format string
which breaks the assumption.

 - re-worked how `bxp` deals with the `sym` input
 - minor pep8
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