Fix #1799: path collections with NaNs in the path cause exceptions in vector backends.
Merge pull request #1799 from mdboom/issue1799

Corrupt/invalid PDF and EPS files when saving a logscaled plot made with negative values
draw paths in stretches of 100 points to avoid the severe decrease in performance that may occur if long paths are draw
Added modifier key event handling for the macosx backend and cleaned up key event handler.
Fix the clippath renderering so that it uses no-clip unsigned chars
typo, break lines >80 char, add link to cmaps list

some lines with links extended past 80 char, broke them up, which shouldn't affect the links.
BF - prevent a TypeError for lists of vertices
fill_betweenx signature fixed
Merge pull request #1854 from ajdawson/bugfix-marker-list

BF - prevent a TypeError for lists of vertices
Merge pull request #1853 from montefra/fill_betweenx

fill_betweenx signature fixed
fill_betweenx signature fixed
Fix issue #1844 in custom_scale_example.py
The rcParam lines.marker should not be used for gridlines
Add a test
Add test
Merge pull request #1846 from mdboom/agg-clip-rendering-fix

Fix the clippath renderering so that it uses no-clip unsigned chars
Merge pull request #1796 from mdboom/gridline-markers

axes.grid lines using lines.marker settings?
Merge remote-tracking branch 'upstream/v1.2.x'

Conflicts:
	lib/matplotlib/tests/baseline_images/test_axes/polar_axes.pdf
	lib/matplotlib/tests/baseline_images/test_axes/polar_axes.png
	lib/matplotlib/tests/baseline_images/test_axes/polar_axes.svg
	lib/matplotlib/tests/baseline_images/test_axes/single_point.pdf
	lib/matplotlib/tests/baseline_images/test_axes/single_point.png
	lib/matplotlib/tests/baseline_images/test_axes/single_point.svg
	lib/matplotlib/tests/test_axes.py
	src/_backend_agg.cpp
Tagging version 1.2.1rc1
Updated to not use NSDictionary literals for pre-obj2.0 compiler support.