testing: convert function names to MPL coding standard
testing: initial spine test (test for SF#2852168)
testing: add new, simplified testing infrastructure
testing: move image comparison functions into matplotlib.testing
testing: workaround issue with nose testing's ZeroNinePlugin
testing: allow fail_condition to be 'indeterminate' for knownfailureif decorator
testing: add KnownFailureDidNotFailTest
Fix bug related to autoscaling and masked values in quiver
textpath.py: import texmanager only when required
textpath support mathtext and tex
