[DOC Beta] Add @since tags for new apis added in 1.5.1 and planned for 1.6.0.
Merge pull request #4899 from bmac/more-since-tags

[DOC Beta] Add @since tags for new apis added in 1.5.1 and planned for 1.6.0
[DOC Beta] Document the didTransition and loading action events
Merge pull request #4846 from bmac/didtransition-docs

[DOC beta] Document the didTransition and loading action events
Rename packages_es6/* to packages/*.

Now that the incremental ES6ing effort is completed, we can move these
packages back into the packages directory (since all packages are
updated to ES6 now).

Discussed in the core team meeting on 2014-05-19.
added building message to build.js
Merge pull request #4901 from GavinJoyce/gj/build-message

added building message to build.js
Merge pull request #4900 from rjackson/move-back-to-packages

Rename packages_es6/* to packages/*.
[FEATURE query-params-new] Model dep state and bugfixes

Such model dependent state.

Query params values are stored in an application cache
using cache keys calculated from Route#serialize params.
At some point this concept will be generalized, but
for now, only query params have model dependent state.

The caching behavior can be configured via a
`cachedProperties` hash on the controller:

    Controller = Ember.Controller.extend({
      queryParams: ['foo'],
      foo: 123,
      cachedProperties: {
        foo: 'controller'
      }
    });

By default, a property's cachedProperties setting is 'model',
as in model-dependent state. The code above uses the only other
option presently available, which is to cache the property scoped
only to the controller, and not to the model currently loaded into
the controller. Practically speaking, this means that query param
values will will be preserved even when switching the model loaded
into a route/controller.