Refactor and unify way how modals are shown
Change save action to return json response
Change save action to return json response
Add styles for danger and warning actions
Global refactor of how modal popus are used:
- create separate js library with all functions to show/hide/config modals
- move modals templates to separate html file
- make existing modals to use new library and templates

Confirmation for synchronous save is added
Fix closing of the "move keys" popup
Merge remote-tracking branch 'upstream/master'