deprecate phetcommon

[pixelzoom]

Discussed at 2/5/15 developer meeting. Make this repo go away. Move preload scripts to chipper. Move other stuff to where it makes sense.

[pixelzoom]

Preload scripts were moved to chipper.initialize-globals.js. There are 7 .js files that need to find a new home:

[pixelzoom]

I don't see PerformanceMonitor used anywhere, can it be deleted?

[samreid]

I have been considering using @mrdoob stats like that but no plans to do so at the moment. I think it is good to delete for now and we can revisit if/when we want it in the future.

[jonathanolson]

Note: maintenance releases to statistics will be trickier after a move of google-analytics.js