Merge pull request #59 from alaframboise/master

Added Demographic Maps explorer, added Geoservices.Server() jsonp, updated index.html
Update README.md
Removed < from mobile.html demo
Added comments and fixed mobile.html
Added image and license.txt
Fill out rest of README.md

- added code, links to image
- added license and resource info
Merge branch 'master' of https://github.com/Esri/esri-leaflet

# By Allan Laframboise
# Via Allan Laframboise
* 'master' of https://github.com/Esri/esri-leaflet:
  Fill out rest of README.md
  Update README.md