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/input/ipaccess.c b/openbsc/src/input/ipaccess.c
index 73d798f..943a5e8 100644
--- a/openbsc/src/input/ipaccess.c
+++ b/openbsc/src/input/ipaccess.c
@@ -32,9 +32,9 @@
 #include <sys/ioctl.h>
 #include <arpa/inet.h>
 
-#include <openbsc/select.h>
-#include <openbsc/tlv.h>
-#include <openbsc/msgb.h>
+#include <osmocore/select.h>
+#include <osmocore/tlv.h>
+#include <osmocore/msgb.h>
 #include <openbsc/debug.h>
 #include <openbsc/gsm_data.h>
 #include <openbsc/abis_nm.h>
@@ -42,7 +42,7 @@
 #include <openbsc/subchan_demux.h>
 #include <openbsc/e1_input.h>
 #include <openbsc/ipaccess.h>
-#include <openbsc/talloc.h>
+#include <osmocore/talloc.h>
 
 /* data structure for one E1 interface with A-bis */
 struct ia_e1_handle {