permit --disable-usb to turn off support for sniffing USB interfaces
Fix the pcap_create() versions for specialized builds.

dag_create() and septel_create() now take a third argument; pass it if
we're building a specialized "support only XXX capture devices" version
of libpcap.
Merge branch 'master' of git+ssh://bpf.tcpdump.org/tcpdump/master/git/libpcap
updates to CHANGES for libpcap 1.7