The standard keyboard shortcut for switching the keyboard layout is Command-
Space, but the Mac driver never sees the Space key press.  So, Wine only sees
a press and release of Alt, which puts focus on the menu bar.  This prevents
that focus change.

The Mac driver doesn't normally steal focus, but a press of a hot key counts
as the user giving permission.

Partially based on a patch for winex11 previously submitted by Vincent Povirk.

It's fairly common in Mac keyboard layouts that, if you type a dead key twice,
the second key press will both produce a non-dead character and also
perpetuate the dead-key state.  For example, with the U.S. layout, Option-E,
E will produce "é" and Option-E, Option-E, E will produce "´é".  Windows
keyboard layouts don't tend to do this.  The second key press produces the
non-dead character and clears the dead-key state.

Developed with Aric Stewart.

winemac: Build a map from Mac virtual key codes to Win32 vkeys and scan codes based on Mac keyboard layout.