Start breaking up Ember.View code into mixins based on purpose

[ebryn]

@mmun @krisselden

[drogus]

I'm curious, what's the purpose of this refactoring? Do you think these could be used outside of View or is it more for separation of concerns?

[ebryn]

@drogus I'm working on "metal views", the view layer performance improvements. Generally, I think it's useful to break apart massive classes such as Ember.View into their logical pieces so you can easily see how things fit together.

[rwjblue]

I'd like to see these mixins in separate files instead of all in the same place, but clearly that can be a later refactoring.

[drogus]

I'm working on "metal views", the view layer performance improvements

Sounds great!