* _WindowAt() and _CountWindows() now have an individual version of that
code which should be magnitudes faster.
* _WindowQuitLoop() no longer handles hidden windows specially - instead,
it now walks the window list in the correct direction which should fix
the issues.
* Also, it now uses WindowAt() and thus has an up-to-date view of the
window list (it will no longer ignore new windows).
* And finally, it will no longer dereference an unsafe pointer (for
BWindow::IsFilePanel()).
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21505 a95241bf-73f2-0310-859d-f6bbb57e9c96