Changes contributed by Bernie Bright <bbright@c031.aone.net.au>

Changes contributed by Bernie Bright <bbright@c031.aone.net.au>
 - The new classes in libmisc.tgz define a stream interface into zlib.
   I've put these in a new directory, Lib/Misc.  Feel free to rename it
   to something more appropriate.  However you'll have to change the
   include directives in all the other files.  Additionally you'll have
   add the library to Lib/Makefile.am and Simulator/Main/Makefile.am.

   The StopWatch class in Lib/Misc requires a HAVE_GETRUSAGE autoconf
   test so I've included the required changes in config.tgz.

   There are a fair few changes to Simulator/Objects as I've moved
   things around.  Loading tiles is quicker but thats not where the delay
   is.  Tile loading takes a few tenths of a second per file on a P200
   but it seems to be the post-processing that leads to a noticeable
   blip in framerate.  I suppose its time to start profiling to see where
   the delays are.

   I've included a brief description of each archives contents.

Lib/Misc/
  zfstream.cxx
  zfstream.hxx
    C++ stream interface into zlib.
    Taken from zlib-1.1.3/contrib/iostream/.
    Minor mods for STL compatibility.
    There's no copyright associated with these so I assume they're
    covered by zlib's.

  fgstream.cxx
  fgstream.hxx
    FlightGear input stream using gz_ifstream.  Tries to open the
    given filename.  If that fails then filename is examined and a
    ".gz" suffix is removed or appended and that file is opened.

  stopwatch.hxx
    A simple timer for benchmarking.  Not used in production code.
    Taken from the Blitz++ project.  Covered by GPL.

  strutils.cxx
  strutils.hxx
    Some simple string manipulation routines.

Simulator/Airports/
  Load airports database using fgstream.
  Changed fgAIRPORTS to use set<> instead of map<>.
  Added bool fgAIRPORTS::search() as a neater way doing the lookup.
  Returns true if found.

Simulator/Astro/
  Modified fgStarsInit() to load stars database using fgstream.

Simulator/Objects/
  Modified fgObjLoad() to use fgstream.
  Modified fgMATERIAL_MGR::load_lib() to use fgstream.
  Many changes to fgMATERIAL.
  Some changes to fgFRAGMENT but I forget what!