feat($compile): isolate scope properties in controller context via controllerAs

It is now possible to ask the $compiler's isolate scope property machinery to 
reference properties by their isolate scope.

The current syntax is to prefix the scope name with a '@', like so:

```js
    scope: {
     "@myData": "=someData",
     "@myString": "@someInterpolation",
     "@myExpr": "&someExpr"
   },
   controllerAs: "someCtrl"
```

The putting of properties within the context of the controller will only occur
if controllerAs is used, and the @-prefix is kind of a gross sort of magic.

Benefits:

  - $scope[controllerAsName] is available to the controllers constructor
  - isolate scope properties are also available to the controllers constructor
  - It is now possible to defer calling of an object's constructor via $injector.instantiateLater

Problems:
  - The '@'-prefix syntax is gross and I don't like it one bit.
  - Extending the directive API is gross and I don't like it one bit.
  - Adding new APIs to the injector is gross and I don't like it one bit.
  - Some of the refactoring will likely have minor performance implications
  - It's possible that there are bugs not being hit due to lack of tests

Related to #7635
can you add this as private comment into the code?