- Import the srslog project into srslte.
- Ported srsue app to use the new logging framework.
- Implemented a wrapper that dispatches log entries to srslog.
- Renamed an existing log test to be more specific to avoid name clashes.
it seems that exit() causes problems when threads couldn't be stopped
properly, which is the reason why we have to call alarm() in the first place.
therefore, send a SIGKILL to our process and make sure we don't leave any
zombie threads running.
the signal handler is the same for all three apps. The "running" flag
as well as the file_logger object are in the common header in order
to allow the signal handler to flush the file if the alarm goes off.