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/src/panic.c b/src/panic.c
index 5fb7b56..21e8fd5 100644
--- a/src/panic.c
+++ b/src/panic.c
@@ -22,6 +22,7 @@
 
 #include <osmocore/gsm_utils.h>
 #include <osmocore/panic.h>
+#include <osmocore/backtrace.h>
 
 #include "../config.h"