More doc cleanup

* Rename the `source` folder to `docs`
* Docs now build to `docs-build`
* Add the [grunt gh-pages](https://github.com/tschaub/grunt-gh-pages) plugin
* WKT parser docs
* Fix bug with duplicate headers in table of contents
* Move all docs out of the `/documentation/*` folder into root to simplify urls
* Refactor the install page to go by module instead of by Node/Bower/CDN
* Move images on homepage to the right side of each block
* New tag line on homepage with link to getting started page and install page
* Link footer to http://pdx.esri.com
* Tweak padding for single line code blocks
* Tweak alignment on back to top and header links
* TOCs will only use `h2`, `h3` and `h4`s for the table of contents
* Remove all old documentation content (old docpad, old documentation files)