Make ADDLOBJ be the list of additional objects to link in when building

Make ADDLOBJ be the list of additional objects to link in when building
a shared libpcap and add into the archive when making an archive
library.  Make V_LIBS in the configure script, and LIBS in the Makefile,
a list of additional libraries with which to link a shared libpcap and
with which to link applications built with a non-shared libpcap.