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/gsm_04_80.c b/openbsc/src/gsm_04_80.c
index d3b472f..8271274 100644
--- a/openbsc/src/gsm_04_80.c
+++ b/openbsc/src/gsm_04_80.c
@@ -29,11 +29,11 @@
 #include <string.h>
 #include <errno.h>
 
-#include <openbsc/msgb.h>
-#include <openbsc/tlv.h>
+#include <osmocore/msgb.h>
+#include <osmocore/tlv.h>
 #include <openbsc/debug.h>
 #include <openbsc/gsm_data.h>
-#include <openbsc/gsm_utils.h>
+#include <osmocore/gsm_utils.h>
 #include <openbsc/gsm_04_08.h>
 #include <openbsc/gsm_04_80.h>