may fail to link because does not use pcap-config

[infrastation]

When tcpslice tries to link with libpcap that was built with dependencies on libnl, libusb or libdbus, the linking fails because tcpslice does not use pcap-config --libs --static to tell any extra libraries (as tcpdump does):

gcc -O2 -DHAVE_CONFIG_H   -D_U_="__attribute__((unused))" -I. -I./../libpcap   -o tcpslice tcpslice.o gmt2local.o gwtm2secs.o machdep.o search.o sessions.o util.o version.o strlcpy.o ./../libpcap/libpcap.a 
./../libpcap/libpcap.a(pcap-linux.o): In function `nl80211_cleanup':
/home/denis/libpcap/./pcap-linux.c:673: undefined reference to `genl_family_put'
[...]
./../libpcap/libpcap.a(pcap-canusb-linux.o): In function `canusb_close':
/home/denis/libpcap/./pcap-canusb-linux.c:329: undefined reference to `pthread_join'
/home/denis/libpcap/./pcap-canusb-linux.c:333: undefined reference to `libusb_close'
[...]
./../libpcap/libpcap.a(pcap-dbus.o): In function `dbus_write':
/home/denis/libpcap/./pcap-dbus.c:114: undefined reference to `dbus_message_demarshal'
[...]
collect2: error: ld returned 1 exit status
Makefile:92: recipe for target 'tcpslice' failed
make: *** [tcpslice] Error 1

This is a low-priority issue but whoever would be willing to work on it should consider moving tcpslice-specific source files (gwrm2secs.c, search.c, sessions.c, tcpslice.c, util.c, version.c and vfprintf.c) into the tcpdump repository to avoid duplicate maintenance work in future.

[guyharris]

It now does the same things to configure libpcap that tcpdump's configure script does.

[infrastation]

I confirm the fix, thank you very much for porting the autotools props.