From: Max Horn
Subject: Auto hide mouse & other changes

the attached bug adds the auto-hide-mouse feature I talked about
earlier. Turned out it was a lot simpler than I thought, simply by
using our existing code :-). I actually spent much more time on fixing
various bugs in the code and correcting (IMO) some behavior (although,
due to the lack of real specs for SDL, it's probably arguable what
'correct' means...).

* adds auto (un)hiding of mouse depending on whether it is in- or
outside the game window
* computation of course coordinates is correct now (it often and
reproducible got out of sync with the old code, since the NSEvent
window was in some cases *not* our window anymore, so locationInWindow
returned wrong results)
* added a method which at any time returns the mouse coords, relative
to our window
* fixed handling of lost/gain input/mouse/app focus "events"

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%40780