dvdnav.patch: prefixed all non-static functions in the included libdvdread.

 dvdnav.patch: prefixed all non-static functions in the included libdvdread.
  This fixes dvdsimple on OS X (either it crashed complaining about
  multiple definitions in the dvdnav and dvdread plugins, or it tried
  to use the libdvdread routines from the dvdnav plugin even though
  the dvdread access is used, but this modified libdvdread doesn't
  seem to be binary compatible... big mess here)
 ALL: fixed a minor libdvdread bug + cleaned the BeOS patch