Initial integration of abstract rendering

Abstract rendering framework integration working for count-based analysis.  Includes slots for aggregator, info, chains of shaders and a few basic shaders. 

Notes: 
* Requires separate installation of abstract rendering, but it prints an error if the import fails, including instructions for how to download/install from the main AR repo
* Axis ticks are wrong...just plain wrong.  Don't trust them when using AR.
* Merged in master at 2:46am on 13Jun2013.


Run examples/plotting/server/abstractrender.py yields....
![ar](https://cloud.githubusercontent.com/assets/2963989/3267190/51361f2e-f2c6-11e3-80b3-66f5833868a5.png)

@bryevdv, we may run in naming conflicts soon with this design. Plus this requires to load almost all modules for no reason which affects requirejs. That's minor but if we are going to split bokehjs into modules then this is something that needs to be resolved.