starting to reorganize maki.
adding individual icons.
separating maki icons
Merge branch 'icon-reorganization' of github.com:mapbox/maki into icon-reorganization
File name fixes
Shell script to render PNGs and sprites.
Add automatic CSS generation to render script

- icon list is now based on maki.json instead of filesystem
- CSS background positions calculated and added to CSS by script
Add ImageMagick-generated PNGs
Add Retina PNGs
Rename dirs for 0.1 compatibility
Update documentation

- Docs updated for new layout/process
- ArcGIS README merged into the main README
- Contributing information separated out of README into CONTRIBUTING.md
Remove redundant info
Sensible grammar.
Clarify render script section
Merge pull request #84 from mapbox/icon-reorganization

Icon reorganization