marshaler.

One or more invoke flags can be passed into IDispatch::Invoke, but we
only care if INVOKEFLAG_PROPERTYGET is specified, and don't about any
others.

dropped in queue_hardware_message. This should fix some problems with
the Alt key getting "stuck" after Alt-Tab.

the audio tab.

- Change select timeout from 2 seconds to 500 microseconds.
- Add test to make sure select wakes up after a closesocket.
- Add test to make sure listen fails without bind.