allowing to set an arbitrary uid, gid and mode for the vfs (like
mounting a dos Filesystem under Linux).
Can be used to mount eg. an upload dir writable only by Admins:
filemanger/cli.php mount --user root_admin --password whatever \
filesystem://dummy/var/www/html/uploads?group=Admins&mode=075 \
/uploads
Please note that you can NOT use filesystem:/something!
Fixed the vfs-classes to deal correctly with get-parameters used as
mount-options.
