Revert rev. 1.86 by jmallett@ as it breaks "ro" mounts specified

Revert rev. 1.86 by jmallett@ as it breaks "ro" mounts specified
in /etc/fstab.

This has been happening due to the priority inversion; options
specified on the command line should take precedence over options
from fstab over default "noro" option, but since both the default
"noro" and options specified on the command line (-w, -r, -o ...)
were put into the same "options" variable, "noro" took precedence
over fstab "ro" (this is easily visible with "mount -d").

PR:		bin/100164