zsh completion: update mq commands completion...
zsh completion: update mq commands completion
* add qclone command;
* qapplied/qunapplied: add --last/--first;
* qdiff: add all diff options;
* qfold: add --force, --no-backup;
* qgoto: add --keep-changes;
* qimport: add --git, --push;
* qnew: add user- and date-related options;
* qpop/qpush: add --keep-changes and --no-backup, drop --name;
* qpush: drop deprecated --merge;
* qrename: complete only unapplied patches' names;
* strip: add --rev, --keep, --bookmark, update descriptions, drop --backup.
