Meta viewport, CanvasRenderer

Added meta viewport (#65). I chose this form because it seems to be the most cross-browser friendly. I'm open to debating that.

Instantiated CanvasRenderer where WebGL is unavailable, implemented in a short private function (#70). I left the `console.log()`s in place as they seem to be productive elsewhere in the project. Tested, and functions in the iOS 7 Simulator* and Android 4.3 / Nexus 4 emulator.

(* No WebRTC in Safari so taking the actual picture doesn't work; nor, obviously, does the swf fallback.)