The create and edit pages of a user had one form for both, ordered for
editing: permissions first, the name and password folded below them and
the quota folded and closed at the end; a new user's name came last.
Both pages now go Account (name, password, may sign in), Role, Quota,
then Groups and permissions, each section with what it is for beside its
fields. Template editor and Superuser become one Role choice with User:
choosing Superuser hides the quota and permissions, which a superuser
does not need (no quota check applies, every permission is theirs); it
keeps the is_staff it had. The quota is always open: each limit takes a
number from 0, or No limit, which is kept as -1 as before; memory is
entered in GiB and kept in MiB, shown exactly so saving a user again
changes nothing. The button says Create user or Save changes.
