Import MPLS (Multi Protocol Label Switching)

MPLS support partly based on the (abandoned?) AYAME project.
Basic LSR (Label Switch Router) functionality is present, but not fully
functional yet.
It is currently possible to insert entries in the LIB (Label Information Base)
with route(8), but setting the operation type is not supported yet.
Imported to allow more people to work on this in the coming weeks.
ok claudio@ laurent@ dlg@

src/include/Makefile

@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.142 2008/03/22 10:36:11 matthieu Exp $
+#	$OpenBSD: Makefile,v 1.143 2008/04/23 10:58:34 norby Exp $
 #	$NetBSD: Makefile,v 1.59 1996/05/15 21:36:43 jtc Exp $
 
 #	@(#)Makefile	5.45.1.1 (Berkeley) 5/6/91
@@ -34,8 +34,8 @@ MFILES=	float.h frame.h
 LFILES=	fcntl.h syslog.h termios.h stdarg.h stdint.h varargs.h
 
 DIRS=	arpa protocols rpc rpcsvc
-LDIRS=	crypto ddb dev isofs miscfs net netatalk netinet altq \
-	netinet6 netnatm net80211 netbt nfs scsi sys ufs uvm xfs
+LDIRS=	altq crypto ddb dev isofs miscfs net netatalk netinet netinet6 \
+	netmpls netnatm net80211 netbt nfs scsi sys ufs uvm xfs
 
 # Directories with an includes target
 RDIRS=	../lib/libpthread ../lib/libcompat ../lib/libcurses \