Reduce the number of states generated by the CPS transformer

This pushes consecutive statements into the same State where possible.

Review URL: https://api.github.com/repos/google/traceur-compiler/issues/835

Closes #835.
replace ModuleStore.get with System.get

I tried this out to see if I could fix the issues, but didn't get any tests breaking.

If you let me know what's not working I'd be happy to assist looking into it.

Review URL: https://api.github.com/repos/google/traceur-compiler/issues/833

Closes #833.
Add a logo

This logo was created by Isaac Durazo (https://github.com/isaacdurazo)
and Sean Mize (https://github.com/mize)
based on https://github.com/voodootikigod/logo.js

Fixes #819

Review URL: https://github.com/google/traceur-compiler/pull/849

Closes #849, closes #819.
Merge branch 'master' into symbol-expand

Conflicts:
	bin/traceur.js