Create zfsinstall-geli-1disk-beta

Here's a mod of mmatuska's zfsinstall to use GELI (and optionally GNOP without GELI to force set zpool ashift=12)

Issues:
- install 1 disk only, use zfsinstall-adddisk-geli-beta to add zpool mirror disk after.
- do not shuffle the physical disks, must keep the disk in same boot order (ada0 ada1)
- requires geom_nop.ko, zlib.ko, crypto.ko, geom_eli.ko

Passwordless GELI (unsecure):
- add "-P" right after "geli init"
- add "-p" right after "geli attach"