REL: v2.0.0rc1

This is the first release candidate for mpl v2.0

This release includes:

 - A re-implementation of the way margins are handled during auto
   scaling to allow artists to 'stick' to an edge of the Axes
 - Improvements to the ticking with log and symlog scales
 - Deprecation of the finance module.  This will be spun off into a stand-alone package
 - Deprecation of the 'hold' machinery
 - Bumped the minimum numpy version to 1.7
 - Standardization of hatch width and appearance across backends
 - Made threshold for triggering 'offset' in `ScalarFormatter` configurable
   and default to 4 (plotting against years should just work now)
 - Default encoding for mp4 is now h264
 - `fill_between` and `fill_betweenx` now use the color cycle
 - Default alignment of bars changed from 'edge' to 'center'
 - Many bug and documentation fixes