Do not check for the D3D device being lost up to 1000 times per second.

This turns out to be very slow, and causes perceivable event lag. The
device loss is still detected during display flip. The logic is altered to
check whether device is lost (as reported by the d3d_display->device_lost
flag which is set during the flip) and then handle the reset logic.
Testing has shown that this seems sufficient to recover from a lost
device without crashing/losing bitmap data.
Switch to using unicode windows.

This fixes al_set_window_title with unicode strings.