Add missing property `namespace` to `DS.RESTAdapter`

It is kindness that public API is clearly specified.
Move unit test for JsonSerializer to serializers directory

The test for the RESTSerializer already is in this directory so this
change adds some consistency.
Merge pull request #886 from pangratz/move_json_serializer_test

Move unit test for JsonSerializer to serializers directory
Merge pull request #774 from tricknotes/add-missing-property

Add missing property `namespace` to `DS.RESTAdapter`
`DS.Adapter.resolveMapConflict` can receive two arguments
Better YUIDocs
Merge pull request #890 from thomasboyt/docs

Better YUIDocs
Merge pull request #887 from tricknotes/remove-not-referenced-argument

`DS.Adapter.resolveMapConflict` can receive two arguments
Eliminate unused variables

I used jshint with '"unused": true' option.
Merge pull request #888 from tricknotes/eliminate-unused

Eliminate unused variables
bump ember to rc2
Ember source now comes from the ruby gem.
ember now comes the from ember-source gem

Reduce some confusion
Merge pull request #892 from stefanpenner/remove_extra_ember

ember now comes the from ember-source gem
Notify that a default adapter type has been selected

This will notify that in the absence of custom adapter
a default has been selected.
link to s3 builds in README
Merge pull request #896 from fivetanley/readme-for-s3-builds

link to s3 builds in README
Merge pull request #891 from stefanpenner/upgrade_to_ember_rc2

Upgrade to ember rc2
Test registerEnumTransform on Adapter class instead of adapter instance

As the registerTransform is call on the class, the registerEnumTransform should operate on the class as well
Allow call to registerEnumTransform on Adapter class, fix #786