Also some code simplifaction

Change demux2 capability values so the lua demux2 gets called as a last resort (2) right before the ps demux is forced (1).

* fixed 2 segfaults when switching categories within the preferences. The options for CONFIG_SUBCATEGORY and CONFIG_CATEGORY aren't displayed, yet.

Don't use enums. They are cool and all (the compiler even tells when one case is missing in switch), but I don't want the compiler to assume as yet unassigned codepoints will not be used.

Add warning if people try using an unimplemented aout function (zorglub!!!). This is currently only possible through the qt interface (i haven't tried it myself).

* strongly improved the speed of make VLC.app and make VLC-release.app by only copying the xcode project and the Resources folder instead of various plugins and most importantly the framework to a temporary folder

 -- There is no "auto size" feature as in the wx interface to
 automatically resize the interface so the video is displayed in its
 native size.
  -- The interface doesn't resize itself down to its minimal size when
  video playback is stopped and the control widgets re-organise themselves
  in a weird way.
Should fix part of playlist resizing.

* added navigation controls to the Help window (implemented with minimal affords by using WebKit's builtin methods). We need a nicer home button graphic, though ;-)