Add more "disconnect" events

[andreasjunestam]

In case the machine is locked with wired ether and / or AC disconnected, we should add more triggers to the code. This could include:

• gyros (like the ones in some Lenovo's)
• wifi AP signal strength (must look at multiple APs so that it does not trigger if one AP goes away)
• ...

[andreasjunestam]

Sweet, seems like the Sensor API (win 7 only) can do this for us:
http://msdn.microsoft.com/en-us/library/windows/desktop/dd318953(v=vs.85).aspx

[andreasjunestam]

Requested so far are:
USB / Firewire
accelerometer
Wifi (need to be careful with this one)