Cleanup YUIDocs.

After reviewing the updated docs as a module within the Ember docs, I came up with a few tweaks/changes that make things show up much better.

Some screenshots of the integrated docs:

Module listing:

![screenshot](http://take.ms/iTl8m)

`Ember.RSVP` Index:

![screenshot](http://take.ms/p4o8V)

`Ember.RSVP.Promise` Index:

![screenshot](http://take.ms/SzyAC)

`Ember.RSVP.EventTarget` Index:

![screenshot](http://take.ms/xdVgG)

FYI - This took much time to track down: apparently YUIDoc falls down and dies if you have an empty line after an opening comment block (`/**`). If that is the case then all other formatting is thrown off within that block.