Make analyzer its own framework, add docs, etc.

[Jesse Squires]

It would be awesome to make swift-proposal-analyer its own Cocoa framework.

• Extract playground Sources/ into a Cocoa framework
• Use jazzy to generate docs
• Add tests
• Setup travis-ci
• Import this framework into the playground

[Jesse Squires]

Using frameworks with playgrounds:

http://www.0xc0deshop.com/2014/11/using-library-code-with-a-swift-playground.html

[Jesse Squires]

Docs is setup, still need to write them

[Jesse Squires]

Follow-up tasks at #9 and #10 for docs and tests

[Jesse Squires]

travis: dbfc934