Dev api rebased

I have changed Build.scala to add projects macroglBuffer and macroglWebgl.
I have switched the version of scala from "2.11.0-RC4" to "2.11.0" too. I hope it's not a problem (apparently some libraries for scalajs are not available for the release candidate).

The WebGL back-end still needs more testing. I have just made sure everything compile without errors and tried a basic example with a canvas in a HTML page, based on scala-js-example-app.