---pre6-----------
                Removed the last idiv from bitmask.c. It should
		now be marginally faster.
	
		Cleanups and fixes everywhere.
		
		Added a font_t struct, which enables us to use
		several bitmap fonts in the game. Created small
		font.
	
		Modified smoke.pov a little to start slight larger than
		a small dot. This looks better with the cannon etc.
		
		Fixed refcounting bug so that the refcount can be
		incremented inside sprite_type.create_sprite
		without problems. calloc() _must_ be used when
		allocating memory for each sprite!

	        Merged with Eero Tamminen. Bonus and wind stuff are among
		the new features. The bird type is also a creation
	        of Eero. Nice! Initial particle engine support also
		by Eero Tamminen.
	
		Changed prototypes from f() to f(void).
		
		Animations now know of their first frame, which
		simplifies coding in some instances. Looping
		is now the default behaviour at the end of an
		animation.
	
		(Partial) Support for larger levels added.
	
		Dirty rectangle handling is separated into its
		own source file.
	
		Added CRITICAL(..) macro. It works like assert(),
		except that the argument is always evaluated,
		even in a 'release' version. Previously assert()
		was used incorrectly for this purpose. Use like
		CRITICAL(important_func() == 0);
		
		Rotation is now handled in collisions, for sprites
		that have a full set of frames. This needs some
		more tuning.
	
		Replaced all fixed point variables and
		calculations in the sprite engine with floats.
		This makes everything easier, but changes the
		scale of velocities etc, so things need tuning
		again.
	
		Cleaned up the povray makefile and created
		a script utils/blur.sh which averages frames.
		This makes it possible to use a lower fps,
		and thus save some space. The cannon uses this
		in the turns.
	
		Implemented the cannon model, but there is no	
		good ball. (Easy to fix)
		
		New aerodynamic model, hopefully good enough.
		Tried to do freely rotating bodies, but not stable
		enough yet.

		Added in game frame timing statistics. The standard
		deviation over 32 frames is displayed to judge the
		quality. This should be as small as possible. Target
		frame time is 30 ms.

		Reworked main Makefile to be more compact and general.
		There is now only a single Makefile for all C source,
		and dependencies are handled automatically.
	
---pre5-----------		
		It is now possible to toggle fullscreen mode in the game.
	
		Added a utility to view animations without using the
		main Airstrike code. This is useful when developing 
		animations in Povray, for checking with different
		backgrounds and at different fps values.

		New, more complicated, aerodynamic model. It is still
		not perfect, but allows for more flexibility.

		Reworked config file system to look for a system wide
		file, and then load settings from $HOME/.airstrikerc.
		Added a lot of physical parameters to config file.

		Started working on a 'probe' system so that the
		ai can know if there are other objects nearby its
		plane.

		Better physics. Objects can now have their own mass
		and 'gravity' variable, so we can do floating object
		that still have mass when they collide. 

		Console background. Right now it's just a transparent
		rectangle, but it could be any image. We need a smaller
		font for the console.

		Started implementing the parachute, but it is a bit
		difficult, since it should behave very different from the
		more 'solid' objects.		

---pre4-----------

2002-10-13	Cleaned up and reworked the setup code. Introduced
		a text console for settings. Added in-game setup
		of keybindings and human/AI for the players. Made
		the game stop after a player reaches 5 points, and
		announce the winner. Fixed the broken ai in pre3. 
		Added sound, but it is turned off by default due to
		no good sounds present.

---pre3-----------

2002-10-06:     Added a menu system. It is ugly inside, and subject
		to change!
		Made it possible to choose the number of players to
		be 0,1 or 2 (in the config file, but this should be
		moved to the in-game menu).
		The ai is now worse than before, due to changes in
		the aerodynamics code. It also doesn't stop shooting
		when you die. This must be fixed for 1.0
		Reworked the font system to be simpler and faster.
		Fixed a bug in the alarm code.
		Cleaned up the Makefiles with help from Eero Tamminen.
	
2002-10-05:     Removed the reliance on __attribute__((constructor)).
		There is now a script to scoop up all the sprite type
		names and register them. This is good both for the
		windows port and for the code itself, since the
		type names are needed at compile-time anyway.
		Changed ai and keyboard controllers to use the signal
		based system. They are now more general.
		Modified the biplane code to the new style state/signal
		system. It can be used as an example of how sprite types
		can be coded. Documented the animation system in
		doc/animation.txt. Introduced timers that can be used
		to limit the number of events per second (when firing
		bullets for example). Bombs are limited to 1/s.

2002-10-04:	Introduced an alarm system that sets off a signal
		after a certain time. Improved the reference counting.
		Changed controllers to use signals to communicate with
		its sprite. This should make ai's easier to write. 

2002-10-01..03:	On screen text and symbol support by glyph.c.
		Various improvements.

2002-10-01: 	Alpha channel support in sprites.
		Set the variable sprite_global.opt_alpha
		to 2 to have per pixel alpha, to 1 to
		have per surface alpha, and to 0 to
		have no alpha. This means that all sprite
		images should have an alpha channel!
		The days of bmp images are over.
		It is still possible to use colorkeyed
		images, but then only per surface alpha
		will be effective, so this is not recommended.
