Refactor DocBlocks

[notmessenger]

• use @returns over @return
• use @return {undefined} when function does not return anything
• param types should be their most generic form - Array vs Ember.Array, Object vs Ember.Object - except for cases in which a more specific Ember.* type is warranted.
• types should be capitalized - Number, Boolean, Object, Function - all except for "undefined" which should be all lowercase.