[WIP] Jquery plugin

This is a redesigned version of the jquery widget that is has been part of tangelo.  I'm putting up this PR to collect comments on the API.  Only the basics are implemented at the moment, but you can take it for a spin locally.  `npm install && grunt serve`.  Then go to [http://localhost:8082/examples/jquery-plugin/](http://localhost:8082/examples/jquery-plugin/) for an example.  Also try the docs at [http://localhost:8082/apidocs/$.fn.geojsMap.html](http://localhost:8082/apidocs/$.fn.geojsMap.html), but ignore the mess on the right side of the page.
I wouldn't recommend that.  It will work in some cases, but you will find events from the old map sticking around and other weirdness.  `window.gl` and a function in `vglRenderer` keep references to the original canvas element in private scope and not everything gets updated when you don't reset the `window`.  I'm reluctant to take this out until #154 is closed.