Initial support for export + curses-visualization of measurements

This extends osmo_nitb to offer a UDP feed of real-time measurement
reports, which can be used by (a variety of) external tools for
visualization or other processing.

We also add a small ncurses based tool (meas_vis) which shows a
baragraph display of the last few mobile stations that were active,
indicating their uplink/downlink receive level and quality.

<WARNING>
This sends non-portable structures like gsm_meas_rep over UDP
and assumes the receiver has identical alignment and endianness!  Before
this feature is merged, it either needs to be converted to a unix domain
socket (but they don't do multicast, which would be nice) or the wire
format needs to change into something portable with defined alignment
and encoding
</WARNING>
diff --git a/openbsc/src/libmsc/Makefile.am b/openbsc/src/libmsc/Makefile.am
index 24db2c2..aa7d8ae 100644
--- a/openbsc/src/libmsc/Makefile.am
+++ b/openbsc/src/libmsc/Makefile.am
@@ -2,6 +2,8 @@
 AM_CFLAGS=-Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOVTY_CFLAGS) \
 	$(LIBOSMOABIS_CFLAGS) $(COVERAGE_CFLAGS)
 
+noinst_HEADERS = meas_feed.h
+
 noinst_LIBRARIES = libmsc.a
 
 libmsc_a_SOURCES =	auth.c \
@@ -17,9 +19,9 @@
 			ussd.c \
 			vty_interface_layer3.c \
 			transaction.c \
-			osmo_msc.c ctrl_commands.c
+			osmo_msc.c ctrl_commands.c meas_feed.c
 
 if BUILD_SMPP
-noinst_HEADERS = smpp_smsc.h
+noinst_HEADERS += smpp_smsc.h
 libmsc_a_SOURCES += smpp_smsc.c smpp_openbsc.c smpp_vty.c smpp_utils.c
 endif