Support `Ember::Data::VERSION`

``` ruby
require 'ember/data/source'

Ember::Data::VERSION #=> "0.13"
```
Merge pull request #1019 from tricknotes/version

Support `Ember::Data::VERSION`
Remove unused tasks

Currently ember is managed by `ember-source` gem.
Remove unnecessary comment
Remove unused helper
Remove unused variables
Merge pull request #1021 from tricknotes/remove-unused-tasks

Remove unused tasks
Merge pull request #1020 from tricknotes/remove-unused-valiables

Remove unused valiables
revert to 6c45c7b
English, do you speak it?
Merge pull request #1028 from bcardarella/grammar

English, do you speak it?
bump ember-dev
Add warning
Merge pull request #1032 from ahawkins/empty-root-warning

Add warning when load request, but not data given
removeOrphan possible for saved records too
Merge branch 'embedded-orphan' into new
Merge branch 'new'
Merge branch 'master' into known working branch
Merge remote-tracking branch 'upstream/master'

Conflicts:
	ember-data-source.gemspec