lib/pcap.h has a name that conflicts with /usr/include/pcap.h. When one
wants to include pcap.h from libpcap (i.e.: the one from /usr/include), one
may end up with pcap.h from openvswitch.
This change renames this header to pcap-file.h and updates all
references to this file.
This change was tested with `make distcheck`.
Signed-off-by: Stephane A. Sezer <sas@cd80.net>
Signed-off-by: Ben Pfaff <blp@nicira.com>
