BUG: fixed shape validation for manual conf intervals in boxplots
TST: fixed new test and added baseline PNG
Install numpy as a setup_requires dependency so pip will install Numpy first
Fix installing numpy as a setup-time dependency
Add tests for installing into a completely clean virtual environment.
Python 3 fixes
Rename C++ variables to avoid use of reserved identifiers
Merge pull request #2445 from mdboom/numpy-setup-dependency

Declare Numpy as a setup dependency
Fix #2300: deal with the case where there are no writable directories.
Fix #2425: setters without arguments should not be added to the list of
parameters
Fix #2418: Crash in PDF backend due to complicated clipping pattern.
Fail hard and fast if the testing data is missing
Merge pull request #2425 from mdboom/axis-off-extra

DOC: `axis_off` wrongfuly appears as a parameter to Figure.add_subplot
Merge pull request #2418 from mdboom/pdf-parent-check

AssertionError with quiver, quiverkey, and an additional patch.
Merge pull request #2379 from mdboom/better-message-about-missing-test-data

Make matplotlib.test() print meaninful messages when baseline images are not installed
Updating version to 1.3.1rc1
BUG: gswin64c.exe not detected on Windows

Move the try/except statement into the loop in order to continue, not break, the loop when an exception occurs.
ENH: use checkdep_ghostscript to determine ghostscript executable
Merge pull request #2469 from cgohlke/patch-2

BUG: gswin64c.exe not detected on Windows
Merge pull request #2470 from cgohlke/patch-3

ENH: use checkdep_ghostscript to determine ghostscript executable