potential registry and server spec

here's my thoughts on a component registry and server. not sure what your current plans are @visionmedia 

the main takeaways are:

- separated registry and server
- no pushing releases to a registry like npm - everything is pulled from a source (such as GitHub) or cached locally on a server

i've also included some notes on a potential no-build system. this is really only useful for JS since we rework/autoprefix our CSS anyways. the more i think about it though, the more complicated it gets, but i think it's the direction we'd go when implementing ES6 modules.

(note: i plan to remove everything in implementations.md once we move it out of the spec)