Switch Deferreds to Promises
Map jQuery promise functions to actual functions

Eventually they'll be removed.
Add note about Promise factory
Don't include the es6-promise lib for the browser

Since native promises are here, we should just assume the browser supports them
and require the user to polyfill if it doesn't.
Remove jQuery promise methods
Rename "private" resolve, reject methods
Remove unneeded mapping
"catch" is a keyword in es3
Promises can only be resolved/rejected with one arg
Underscorize Group's resolve and reject methods too
Merge branch 'es6-promises'

* es6-promises:
  Underscorize Group's resolve and reject methods too
  Promises can only be resolved/rejected with one arg
  "catch" is a keyword in es3
  Remove unneeded mapping
  Rename "private" resolve, reject methods
  Remove jQuery promise methods
  Don't include the es6-promise lib for the browser
  Add note about Promise factory
  Map jQuery promise functions to actual functions
  Switch Deferreds to Promises