This patch moves the GSM-specific functions to the new library
libosmogsm which is provided by libosmocore.

I have also moved generate_backtrace() to backtrace.c instead
of gsm_utils.c, otherwise the timer and msgfile tests depend on
libosmogsm.

Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
diff --git a/include/osmocore/backtrace.h b/include/osmocore/backtrace.h
new file mode 100644
index 0000000..bbbb2c2
--- /dev/null
+++ b/include/osmocore/backtrace.h
@@ -0,0 +1,6 @@
+#ifndef _OSMO_BACKTRACE_H_
+#define _OSMO_BACKTRACE_H_
+
+void generate_backtrace();
+
+#endif