New Cesium Coding Guide for Contributors

Hi all,

As part of our effort to onramp new Cesium contributors, we just finished a draft of the Coding Guide:

https://github.com/AnalyticalGraphicsInc/cesium/pull/3312

Please provide your feedback in the pull request (or this thread). Even if you do not plan to contribute to Cesium, you may find many of the practices useful.

Thanks,

Patrick