app: Introduce some routines to help with application startup

The plan is to collect structs and routines for application
setup and remove many copies of the boilerplate code we have
right now. This starts with routines to ignore certain signals
and the stderr init code.

Increment the age of the library because a new interface was added.
diff --git a/include/osmocom/core/Makefile.am b/include/osmocom/core/Makefile.am
index b21e047..3698873 100644
--- a/include/osmocom/core/Makefile.am
+++ b/include/osmocom/core/Makefile.am
@@ -3,7 +3,7 @@
 		   gsmtap.h write_queue.h \
 		   logging.h rate_ctr.h gsmtap_util.h \
 		   plugin.h crc16.h panic.h process.h msgfile.h \
-		   backtrace.h conv.h
+		   backtrace.h conv.h application.h
 
 if ENABLE_TALLOC
 osmocore_HEADERS += talloc.h
diff --git a/include/osmocom/core/application.h b/include/osmocom/core/application.h
new file mode 100644
index 0000000..c1642ec
--- /dev/null
+++ b/include/osmocom/core/application.h
@@ -0,0 +1,16 @@
+#ifndef OSMO_APPLICATION_H
+#define OSMO_APPLICATION_H
+
+/**
+ * Routines for helping with the application setup.
+ */
+
+struct log_info;
+struct log_target;
+
+extern struct log_target *osmo_stderr_target;
+
+void osmo_init_ignore_signals(void);
+int osmo_init_logging(const struct log_info *);
+
+#endif