Fix cryptsetup_shell to handle cryptoption 'allow-discards'

If the encrypted device is unlocked at the console rather than through ssh,
then the cmdline option 'allow-discards' is handled correctly. That is, if
the cmdline contains
  cryptdevice=$device:$name:allow-discards
then encryptssh_hook calls luksOpen with `--allow-discards`.

This patch fixes cryptsetup_shell to do the same.
Bump version to 0.11.1-1
PKGBUILD: Added chadversary as contributor
Bumped version to 0.12-1