meas_feed: Add tool to read meas_feed PCAP and write it to sqlite3

In fact, the DB write code has been split out so we could later also
have a binary that would listen to realtime meas_feed packets and stuff
them into a database without any intermediate PCAP step.

The database schema contains a couple of convenience wrapper views, most
notably the "overview" view.
diff --git a/openbsc/src/utils/meas_db.h b/openbsc/src/utils/meas_db.h
new file mode 100644
index 0000000..889e902
--- /dev/null
+++ b/openbsc/src/utils/meas_db.h
@@ -0,0 +1,17 @@
+#ifndef OPENBSC_MEAS_DB_H
+#define OPENBSC_MEAS_DB_H
+
+struct meas_db_state;
+
+struct meas_db_state *meas_db_open(void *ctx, const char *fname);
+void meas_db_close(struct meas_db_state *st);
+
+int meas_db_begin(struct meas_db_state *st);
+int meas_db_commit(struct meas_db_state *st);
+
+int meas_db_insert(struct meas_db_state *st, const char *imsi,
+		   const char *name, unsigned long timestamp,
+		   const char *scenario,
+		   const struct gsm_meas_rep *mr);
+
+#endif