Merge pull request #40 from astrofrog/reorganization-1

Phase 1 of reorganization
Add astropy-helpers
Added ez_setup.py and expanded MANIFEST.in
More reorganization to match package template
Move Cython code into main pyregion package directory
Added a test for get_mask to make sure the Cython extension gets used in tests
Use plt.savefig instead of plt.show
Tidy up docs build system
Update .travis.yml to package-template version
Set DISPLAY variable
Drop Python 3.2 from .travis.yml
Fix documentation plots
Renamed doc scripts to avoid being mistaken as unit tests
Disable sphinx build with warnings as exceptions since we need to refactor some of the docs to get it to pass.