Yquake2

This is a native port of Yamagi Quake II. A lot of stuff has been rewritten,
so it's more like a fork, but I'm yet to come up with a new name for it. It
includes native renderers, which are 10-20% faster than the original SDL-based
ones, but they are less well tested, so I included both. Support for few mods,
including the official mission packs are also included in the package.

Be sure to read the original readme, most of it still applies to this port:
http://www.yamagi.org/quake2/README

Yamagi Quake II features:
- Anisotropic filtering.
- Compatible with most mods (as long as their source is available).
- From scratch rewritten savegame system.
- Ingame soundtrack playback via OGG/Vorbis.
- Mature and stable codebase.
- No gameplay and graphic enhancements, but optional support for retexturing 
  packs.
- SDL for input, sound and rendering.
- Support for unlimited screen size / resolutions.
- Widescreen support. 

Features specific to this version:
- An enhanced software renderer with limited texture filtering capabilities.
- Fast native sound, renderer, and input code in addition to SDL.
- Automatic Hor+ FOV for widescreen modes (the original port was Vert-, and
  required manual fov adjustment).
- Binary tree search for PAK file access.
  
Changelog
---------

2012-12-07:
- Fixed mods (ctf, rogue, xatrix, zaero) on MorphOS (missing LibNIX
  initialization).
- Fixed window title on MorphOS.
- Fixed pathnames containing whitespace on AROS.
- Unified the source tree of the main game and the mods.
- Tweaked mouse grabbing (backport from the official repo).
- Fixed a few bugs which prevented adding new console commands.
- More reliable CD audio detection. Now all drives are checked for audio
  tracks.

2012-08-30:
- Fixed widescreen FOV calculation. The calculated FOV was too large due to
  a wrong division.
- Changed the default resolution from 640x400 to 640x480 both in software
  and GL.
- Sychronized the name of a few common CVARs between the GL and the software
  renderer
- Fixed the r_speed and r_dspeed CVARs in the software renderer.
- Fixed software renderer's underwater screen warping in widescreen, and
  disabled it for resolutions wider than 1280 pixels, because it caused a
  major slowdown in those.
- Revamped native input handling. This should get rid of the mouse grabbing
  quirks in the native renderers. It also fixes the handling of the mouse
  wheel on MorphOS.
- Fixed 8-bit AHI sound playback.
- Setting s_lib in the console will only take effect after a "snd_restart".
- Got rid of a unused CVAR in the software renderer.
- Widescreen FOV correction is now controllable in the video menu.
- Removed the nonexistent Null sound driver from the menu. You can still
  disable sound by typing "s_initsound 0" followed by a "snd_restart" in
  the console.
- Replaced the linear search with red–black tree for commands, CVARs, sounds
  and PAK file accesses. This improves level loading time, and it should also
  reduce the hitches caused by PAK file accesses. Based on r1q2.
- Added GL and software texture name caching based on r1gl.
- The client now only uses Zone memory allocations, and all the zone blocks
  are freed on exit. This fixes a few lurking memory leaks.
- Hopefully fixed CD audio playback.
- A few small speed improvements.