Revert to rc3 to GSG
Merge pull request #606 from trek/revert-to-rc3

Revert to using RC3 until known matching data SHA
Remove reference to `template` helper.

Seems unnecessary. Plus, if you use `template`, you'll get
an Ember.warn
update home page to be clear ember is 56kb minified + gziped
Merge pull request #607 from machty/deprecate-template

Remove reference to `template` helper.
[fixes #608] fix some typos.

thanks @shellyan for pointing them out.