UX: require confirmation of revoking permissions on
repos/user groups/repo groups. We don't want people to
click on this accidentally.

consistent handling of grant/revoke of permissions widgets
- use 1 method for users and for users groups
- use common JS for ajax revoke
- cleanup code

- Manage User’s Groups: create, delete, rename, add/remove users inside.
by user group admin.
In this case, a user's group can be owned by several people thru an owner user's group.

Some refactoring of naming, permission handling logic.
- remove some code duplicity as well as inconsistent naming

further cleanup of UsersGroup

Renaming some names ... but trying not to change API or database scheme.

"Users groups" is grammatically incorrect English - rename to "user groups"

- and same story with "repositories groups"

This will only change the user facing texts. Names of files, modules, functions
and variables should be changed too.

Autocomplete fixes
- use translation MAP
- move translation to top level in order to be used inside rhodecode.js
- re-use user and groups data in changesets page

fixed inline comment indicator.
- templates cleanup

#56 added ajax removal of users groups,
fixed permission edition templates by regular non admin users
found bugfixes in forms for users groups