split 'libosmocore' from openbsc codebase

This library is intended to collect all generic/common funcitionality
of all Osmocom.org projects, including OpenBSC but also OsmocomBB

The library currently includes the following modules:

bitvec, comp128, gsm_utils, msgb, select, signal, statistics, talloc, timer,
tlv_parse, linuxlist

msgb allocation error debugging had to be temporarily disabled as it depends on
'debug.c' functionality which at the moment remains in OpenBSC
diff --git a/openbsc/src/vty_interface_layer3.c b/openbsc/src/vty_interface_layer3.c
index f2b5728..b824c3d 100644
--- a/openbsc/src/vty_interface_layer3.c
+++ b/openbsc/src/vty_interface_layer3.c
@@ -29,16 +29,16 @@
 
 #include <arpa/inet.h>
 
-#include <openbsc/linuxlist.h>
+#include <osmocore/linuxlist.h>
 #include <openbsc/gsm_data.h>
 #include <openbsc/gsm_subscriber.h>
 #include <openbsc/silent_call.h>
 #include <openbsc/gsm_04_11.h>
 #include <openbsc/e1_input.h>
 #include <openbsc/abis_nm.h>
-#include <openbsc/gsm_utils.h>
+#include <osmocore/gsm_utils.h>
 #include <openbsc/db.h>
-#include <openbsc/talloc.h>
+#include <osmocore/talloc.h>
 #include <openbsc/signal.h>
 #include <openbsc/debug.h>