updated ContentNavigation
Merge branch 'develop' of git://github.com/sulu-cmf/SuluContentBundle into feature/content-navigation-refactoring
corrected response of NavigationController
Merge branch 'develop' of git://github.com/sulu-cmf/SuluContentBundle into feature/content-navigation-refactoring

Conflicts:
	Admin/SuluContentContentNavigation.php
Update composer.json
implemented preview cache provider
refactored preview component
changed controller / message component to fix new interface
implemented to array
enabled change template
fixed content types
added gitignore temp files
refactored preview cache provider
refactor preview service
fixed node controller smart content test
adapted configuration
changed interface for preview controller
fixed preview controller test
fixed websocket component
extracted preview code