Most probably that was related to "pulsating" buttons that haven't
been used since 10.9. Whether the code even worked (made buttons
pulsate) on 10.9 anyway is unclear.

Much of the code in this file uses various HITheme (Carbon?) API that
as far as I know is long since deprecated and undocumented. It's weird
that it still compiles, and that it doesn't get caught by the private
API use checking when submitting to the the Mac App Store, in the
LibreOffice Vanilla case.

This change reduces the busy looping in Dialog::Execute() even when
nothing happens (no user input, no mouse movement) when displaying a
dialog.

Change-Id: I9c62db608f637aa5d8493176feb2873f6426fd00