Merge pull request #2193 from stefanpenner/master

[fixes #2189] #render was declared as @method action
Docs: Ember.run.once with anonymous functions

Added warning in the docs that passing identical anonymous functions to Ember.run.once will still schedule the functions to be called twice.
Merge pull request #2195 from machty/patch-1

Docs: Ember.run.once with anonymous functions
[fixes #2196] Enumberable#firstObject and #lastObject are computed
properties, for property access get should be used. This updates the
documentation accordingly