Uses css-variabled and dom manipulation to change
the projectors h1 color on the fly.
Will have issues with multiple projectors nested in the same view
- use always color black on projector, also in dark mode
- show border for projector preview
- Fix projector logo margin by using img instead of os-logo
- Use also 'username' in invitation email subject
- Add projector logo/headerimage
- Fixed opening multiselect action menu for users.
- Used defined toolbar color for multiselect mode.
- (server) Added check for 'request.data._mutable = True' to edit user
profile as normal user.
