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/include/osmocore/Makefile.am b/libosmocore/include/osmocore/Makefile.am
new file mode 100644
index 0000000..aec27d1
--- /dev/null
+++ b/libosmocore/include/osmocore/Makefile.am
@@ -0,0 +1,2 @@
+pkginclude_HEADERS = signal.h linuxlist.h timer.h talloc.h msgb.h select.h \
+		     tlv.h bitvec.h comp128.h statistics.h gsm_utils.h