babeld: Initial import, for Babel routing protocol.

* Initial import of the Babel routing protocol, ported to Quagga.
* LICENCE: Update the original LICENCE file to include all known potentially
  applicable copyright claims.  Ask that any future contributors to babeld/
  grant MIT/X11 licence to their work.
* *.{c,h}: Add GPL headers, in according with the SFLC guidance on
  dealing with potentially mixed GPL/other licensed work, at:

  https://www.softwarefreedom.org/resources/2007/gpl-non-gpl-collaboration.html
diff --git a/configure.ac b/configure.ac
index 61c4466..4fe70e1 100755
--- a/configure.ac
+++ b/configure.ac
@@ -207,6 +207,8 @@
 [  --disable-ospfd         do not build ospfd])
 AC_ARG_ENABLE(ospf6d,
 [  --disable-ospf6d        do not build ospf6d])
+AC_ARG_ENABLE(babeld,
+[  --disable-babeld        do not build babeld])
 AC_ARG_ENABLE(watchquagga,
 [  --disable-watchquagga   do not build watchquagga])
 AC_ARG_ENABLE(isisd,
@@ -1245,6 +1247,12 @@
   OSPFD="ospfd"
 fi
 
+if test "${enable_babeld}" = "no";then
+  BABELD=""
+else
+  BABELD="babeld"
+fi
+
 if test "${enable_watchquagga}" = "no";then
   WATCHQUAGGA=""
 else
@@ -1301,6 +1309,7 @@
 AC_SUBST(RIPNGD)
 AC_SUBST(OSPFD)
 AC_SUBST(OSPF6D)
+AC_SUBST(BABELD)
 AC_SUBST(WATCHQUAGGA)
 AC_SUBST(ISISD)
 AC_SUBST(SOLARIS)
@@ -1544,6 +1553,7 @@
 AC_DEFINE_UNQUOTED(PATH_BGPD_PID, "$quagga_statedir/bgpd.pid",bgpd PID)
 AC_DEFINE_UNQUOTED(PATH_OSPFD_PID, "$quagga_statedir/ospfd.pid",ospfd PID)
 AC_DEFINE_UNQUOTED(PATH_OSPF6D_PID, "$quagga_statedir/ospf6d.pid",ospf6d PID)
+AC_DEFINE_UNQUOTED(PATH_BABELD_PID, "$quagga_statedir/babeld.pid",babeld PID)
 AC_DEFINE_UNQUOTED(PATH_ISISD_PID, "$quagga_statedir/isisd.pid",isisd PID)
 AC_DEFINE_UNQUOTED(PATH_WATCHQUAGGA_PID, "$quagga_statedir/watchquagga.pid",watchquagga PID)
 AC_DEFINE_UNQUOTED(ZEBRA_SERV_PATH, "$quagga_statedir/zserv.api",zebra api socket)
@@ -1553,6 +1563,7 @@
 AC_DEFINE_UNQUOTED(BGP_VTYSH_PATH, "$quagga_statedir/bgpd.vty",bgpd vty socket)
 AC_DEFINE_UNQUOTED(OSPF_VTYSH_PATH, "$quagga_statedir/ospfd.vty",ospfd vty socket)
 AC_DEFINE_UNQUOTED(OSPF6_VTYSH_PATH, "$quagga_statedir/ospf6d.vty",ospf6d vty socket)
+AC_DEFINE_UNQUOTED(BABEL_VTYSH_PATH, "$quagga_statedir/babeld.vty",babeld vty socket)
 AC_DEFINE_UNQUOTED(ISIS_VTYSH_PATH, "$quagga_statedir/isisd.vty",isisd vty socket)
 AC_DEFINE_UNQUOTED(DAEMON_VTY_DIR, "$quagga_statedir",daemon vty directory)
 
@@ -1577,8 +1588,9 @@
 
 AC_CONFIG_FILES([Makefile lib/Makefile zebra/Makefile ripd/Makefile 
 	  ripngd/Makefile bgpd/Makefile ospfd/Makefile watchquagga/Makefile
-	  ospf6d/Makefile isisd/Makefile vtysh/Makefile doc/Makefile 
-	  ospfclient/Makefile tests/Makefile m4/Makefile redhat/Makefile
+	  ospf6d/Makefile isisd/Makefile babeld/Makefile vtysh/Makefile
+          doc/Makefile ospfclient/Makefile tests/Makefile m4/Makefile
+          redhat/Makefile
 	  pkgsrc/Makefile
 	  redhat/quagga.spec 
 	  lib/version.h