optimize hm counting methods by computing newcol and error only once
add iterative ham conversion
automatic border clipping
asc configuration file
avoid/fix horizontal striping in sliced output
delete SHAMBLACK code
read gif89a
read/write rgbn/rgb8
handle iff input with a masking bitplane by skipping
	the last bitplane or adapting colormap so it can be processed
read/write ppm
check correctness of no, mu, wf, wf2, hs, hs2, con, ehb conversions
read/write sliced EHB
speedups, eg. readiff nextc, profile iff creation, srgr i/o more buffering
profile wf distribution method
use hamlab input filters, read input from stdin, write output to stdout
	either 0 bytes (not recognized) or raw 24bits rgb with an 11 byte
	header:
	char magic[3]="HL2";
	short width;
	short height;
	long unknown=0x00302020;
possibility to read from stdin and write to stdout with - for filename, do
	all messages go to stderr?
use tad input filters