fstab.conf: Add a new "crypttabOptions" option that defaults to "luks".
Document that for Debian and Debian-based distributions, the
setting should be changed to "luks,keyscript=/bin/cat".
main.py: Append the options from the above setting to the end of every
line in crypttab.
At least the "luks" option should always be there, because there may be
different encryption types. The Debian initramfs-tools also require the
Debian-specific keyscript option and will otherwise ignore the keyfile
entirely (see pull request #254).
At least the Debian update-initramfs needs the entry to be there (see
pull request #254). Dracut will probably need it too. And logically, it
should be there.
Having swap set at "none" makes hibernating not possible.
AFAIK, no filesystem/partition sets mountpoint as "none" nor has any other besides swap an empty mountpoint at the stage where the fstab module is called.
Tests so far show this change creates a working fstab when using a swap partition.
