Removed WITH_LIBPCAP_BASE
Removed PKGINSTALL (not necessary)
Added pkg-deinstall to remove user and group
Cleanup of the pkg-plist
Small change to sancp.sh startup script (${PREFIX} == %%PREFIX%%)

Question 1:

The port uses the hardcoded log directory /var/log/sancp/, this
doesn't honour PREFIX. Its not a bad location tough. Shall
I make the log dir configurable and default to /var/log/sancp/ ?

Question 2:

The pkg-message is a bit big, shall I move some of it
to pkg-desc ?