[linux] workaround joystick hotplugging bug in SDL via udev and json-rpc

This is a rather ugly workaround for the joystick hotplug issue and should be removed once our input handling is properly fixed.

It uses a udev rule and json-rcp over TCP to toggle joystick support if a controller is plugged in or wakes from sleep.
based on forum user teeedubbs idea: http://forum.xbmc.org/showthread.php?tid=157499&pid=1722549#pid1722549

I could only test this with a PS3 sixaxis controller, can please anyone test it with Xbox 360.
3rd party controllers probably need additional udev rules, which I'd be happy to add.

@topfs2 ping