Must also s/-/_/g for NAS_PORTS_DIRECT.

Before this change, 'truenas-files' became 'TRUENAS-FILES'
instead of 'TRUENAS_FILES' that the port will pick up.
Re-add zfsd and truenas files.

Somehow zfsd and truenas-files got removed in 647194a.
Use NO_STAGE to avoid problems with missing dirs.

NO_STAGE is required otherwise the needed intermediate
directories aren't made and the install target fails.
set NAS_PORTS_DIRECT to get zfsd+truenas-files

Without this the ports tree will try to download source
tarballs which don't exist.