User/Group namespaces for projects

Fix hash key settings["gitlab_version"] to settings[:gitlab_version]

In backup_create, backup information hash is using symbol as its key.
But in backup_restore, string key is used and it returns empty value.

Added bg for transparent images

Improve user feedback on the Profile > Design page

- Header changes immediately without a page reload
- Lets the user know that we actually saved their setting when changed

added width and height below images in diff