BREAKING CHANGE:
This change moves the http module into angular2/, so its import
path is now angular2/http instead of http/http.
Many other modules have also been moved around inside of angular2,
but the public API paths have not changed as of this commit.
Promise used to be typed as any, giving incorrect results. This change
fixes places that were incorrectly typed and re-exports the actual
Promise type from es6-promise.
It also fixes a series of compilation errors discovered/triggered by
this change.
The semantics between ES6 `Promise#all` and Dart's `Future#wait` are
different for values that are not `Promise`/`Future`s. In ES6,
non-`Promise` values are immediately completed to their current value.
In Dart, non-`Future` values cause an error.
Updated Dart's `PromiseWrapper#all` implementation to conform to the ES6
spec.