winex11: Add a workaround for Metacity being too strict and disabling fullscreen support for not resizable windows.

msi: If a feature's action is INSTALLSTATE_UNKNOWN, MsiEvaluateCondition should return MSICONDITION_FALSE.

dinput: Include fcntl.h instead of sys/fcntl.h since they are equivalent and the former is more portable.

The code required that a row started with a visible band. However this
was not met if the first band of the rebar was hidden. The new code
should fix this case. I've also made it explicit in the comments that
the functions require the first band to be visible and renamed
next_band, prev_band to next_visible and prev_visible to make it clear
what these functions do.