On Windows/Chrome, the first click of the g+ button shows a popup
blocked warning, because the action is deferred while loading the
gplus library. Have the modals load the library first, and enable the
buttons when they're ready.
* Move api loading to FacebookHandler
* Use success callbacks
* Use same, properly named events
* Use same functions and property names
* Refactor related social button, out of use rendering system
* Remove the now unnecessary form split from CreateAccountModal
