Fixed token refresh for clientless access tokens
Added scope reduction to refresh token grant

It is now possible for clients to reduce the scopes for an access token
when refreshing it
Symbols instead of strings for user input.
Symbols instead of strings for user input.
Version bump
Merge branch 'v0.7'

Conflicts:
	CHANGELOG.md
	lib/doorkeeper/version.rb
Merge pull request #326 from ianunruh/master

Fixed token refresh for clientless access tokens
Changelog update
Bugfix: access token scopes are strings

[fixes #329]
Releasing 1.0.0.rc1
mongoid3 test fix