Change to how strlcpy and strlcat are handled

Put strlcpy and strlcat object files back in the source group in lib.
Moved libfko_util.a to the common directory (though sources remain in
lib).  Client and server code looks to common dir for libfko-util.
This fixes issue with strlcpy showing as undefined symbol when perl FKO
module is loaded.
Add AM_CPPFLAGS to common/Makefile.am
Fixed broken configure options for forcing a particular firewall type and path.
merged bf990821ffcb44aba4c82a476e0309b49837ebb7 for #20
remove unused vars for pf/ipfw/ipf firewalls until NAT is supported for them