Added hotplug support for Linux input devices.

I have bluetooth devices in my Raspberry running XBMC. These devices are not present, unless i wake them up. 

This patch makes sure, unplugged devices are recognized and thus freeing the devices handle. New devices are scanned for every 10 seconds and integrated into the existing device configuration w/o flushing old devices.

Also i added a scan for /dev/tty1 to obtain a valid keyboard-layout, since /dev/tty0 is unconfigured in some linux flavours.