Notify UI for device disconnect; resolves #511

Only alert and pause if emu is already playing.
Delay before dispatching events, resolving issue 544
Merge pull request #566 from dethbunny/WiimoteAnalogFix

Delay before dispatching events, resolving issue 544
no need to declare here
Merge pull request #565 from dethbunny/DeviceFix

Notify UI for device disconnect; resolves #511