nhrpd: implement next hop resolution protocol

This provides DMVPN support and integrates to strongSwan. Please read
README.nhrpd and README.kernel for more details.
diff --git a/nhrpd/Makefile.am b/nhrpd/Makefile.am
new file mode 100644
index 0000000..00ecc7f
--- /dev/null
+++ b/nhrpd/Makefile.am
@@ -0,0 +1,35 @@
+## Process this file with automake to produce Makefile.in.
+
+AM_CPPFLAGS = -I.. -I$(top_srcdir) -I$(top_srcdir)/lib -I$(top_builddir)/lib -DQUAGGA_NO_DEPRECATED_INTERFACES
+DEFS = @DEFS@ @CARES_CFLAGS@ -DSYSCONFDIR=\"$(sysconfdir)/\"
+INSTALL_SDATA=@INSTALL@ -m 600
+
+AM_CFLAGS = $(PICFLAGS) #$(WERROR)
+AM_LDFLAGS = $(PICLDFLAGS)
+
+sbin_PROGRAMS = nhrpd
+
+nhrpd_SOURCES = \
+	zbuf.c \
+	znl.c \
+	resolver.c \
+	linux.c \
+	netlink_arp.c \
+	netlink_gre.c \
+	vici.c \
+	reqid.c \
+	nhrp_event.c \
+	nhrp_packet.c \
+	nhrp_interface.c \
+	nhrp_vc.c \
+	nhrp_peer.c \
+	nhrp_cache.c \
+	nhrp_nhs.c \
+	nhrp_route.c \
+	nhrp_shortcut.c \
+	nhrp_vty.c \
+	nhrp_main.c
+
+nhrpd_LDADD = ../lib/libzebra.la @LIBCAP@ @CARES_LIBS@
+
+#dist_examples_DATA = nhrpd.conf.sample