added sortby to colleciton api
added sortBy to media selection
added changelog
Merge branch 'develop' of git://github.com/sulu-cmf/sulu into feature/sort-collections

Conflicts:
	CHANGELOG.md
Merge branch 'develop' of git://github.com/sulu-cmf/sulu into feature/sort-collections

Conflicts:
	CHANGELOG.md
Merge branch 'develop' of git://github.com/sulu-cmf/sulu into feature/sort-collections

Conflicts:
	CHANGELOG.md
	src/Sulu/Bundle/MediaBundle/Resources/public/dist/components/media-selection/main.js
	src/Sulu/Bundle/MediaBundle/Resources/public/js/components/media-selection/main.js
fixed interfaces of colleciton manager
Updated changelog
Merge pull request #529 from sulu-cmf/feature/sort-collections

Sort collections in media-selection overlay