pbrd: add vlan filters pcp/vlan-id/vlan-flags; ip-protocol any (pbr feature)

pbrd: add vlan filters pcp/vlan-id/vlan-flags; ip-protocol any (pbr feature)

    Subset: feature in PBR

    New PBR rule fields:

    match ip-protocol (was only tcp|udp, now any value in /etc/protocols)
    match pcp (0-7)
    match vlan (1-4094)
    match vlan (tagged|untagged|untagged-or-zero)

    Filter flags
	Add filter_bm (flags) field internally to indicate which
	filter fields should be considered active. Bit definitions
	as in lib/pbr.h.

	This commit uses only the PBR_FILTER_PCP bit, but other
	fields will be added in future commits. (Fixes bug related
	to determining set/not-set state of pcp filter)

	Shift vlan filter flags to lib/pbr.h

    Changes by:
	Josh Werner <joshuawerner@mitre.org>
	Eli Baum <ebaum@mitre.org>
	G. Paul Ziemba <paulz@labn.net>

Signed-off-by: G. Paul Ziemba <paulz@labn.net>