Packs font characters into a FNT file.
The first parameter must be the name of the directory which holds the font characters. This directory must contain images with files names like 000.png, 001.png and so on.
The easiest way to initialize a font character directory is using unpackfnt to unpack the original colorf.fnt file from the game.
The second parameter specifies the filename of the FNT file to write. If the parameter is missing or is "-" then the output is written to stdout.