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/libosmocore/libosmocore.pc.in b/libosmocore/libosmocore.pc.in
new file mode 100644
index 0000000..0d09cb8
--- /dev/null
+++ b/libosmocore/libosmocore.pc.in
@@ -0,0 +1,10 @@
+prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Osmocom Core Library
+Description: C Utility Library
+Version: @VERSION@
+Libs: -L${libdir} -losmocore
+Cflags: -I${includedir}/
+