This change adds a separate thread to initialize and read reports from
the supported X52 device. This will then process and raise input events
for a virtual device.
Prior to this change, x52d could only run in the foreground, regardless
of the value of the foreground flag. This change adds the standard
double-fork routine to daemonize the program.
This change also adds a PID file argument to x52d, which is used to
ensure that only one instance of the x52d daemon is running at any time.
This change adds the daemon configuration parser and command line
argument parser. This also adds the associated strings to the
translation files, and integrates the daemon into the existing autotools
build framework.