Merge pull request #43 from mvexel/master

clean up requirements.txt and small changes to readme to allow easy access to setup and api docs.
Add license, fixes #26.

Also, fix CSS and HTML issues. Use a base style. Remove Leaflet
shoutout.
Restyle buttons, simplify styles further
Remove more styles
Fix invalid HTML, and invalid Python
Simplify and unkink models, add install directions to readm
Import the necessary challenges
Merge branch 'master' of git://github.com/mvexel/maproulette

* 'master' of git://github.com/mvexel/maproulette: