colorspace conversions (v2)
	- cal*
	- iccbased
	- how to normalize Lab components to 0..1
	- fast color cubes
	- how to cache colorspace cubes (what key?)

image rendering (v2)
	- tiles
	- dct case
	- better filter than box
	- lazy decoding

shadings
	- ... jeong ...

rendering
	- bbox culling (cache bbox in over node?)
	- image mask + color case
	- merge gka optims
	- optimize inner rendering loops
	- optimize image load/decode/scale
	- special-case optims (1, 2 and 4)
	- cpu-specific optims

parser
	- resource dict generate fake ids
	- try to clean up colorspace/material handling in interpreter
	- annotations and destinations (for links and outline)
	- BPC 2, 4

clean up
	- make source ansi c89 / pedantic
	- reference count everything
	- standard cleanup mechanism
	- design by contract
	- split into private and public
	- comments and documentation

cache
	global cache for cmaps and fontfiles (emb+sys)
	render cache (link-nodes and scaled images)