improve permission handling in views
fix license model validation
Merge branch 'staging' into 640-project_management

Conflicts:
	app/views/ontologies/_menu.html.haml
fix margin of metadata edit buttons in show
fix navigation - more dropdown has no ul
imrpove error message
fix metadata controllers: use correct error handling
add test for projects controller
fix abilities concerning metadata classes
add further metadata controller tests
Merge branch '640-project_management' into develop

Conflicts:
	app/views/ontologies/_menu.html.haml