Command line:

	argument parsing, argv0 handling, help, version, verbose

	plugin mechanisms

	empty graph - all layouts, all formats
	
Render tests:

	node shapes (selected subset, single shape per test, no label)
		peripheries, sides, skew, distort, ellipses
	
	label (single node, invisible box shape):
		 various fonts, encodings, russian, chinese, german, ...
		 text justification, single/multi lines

	colors, formats, transparency, pen, fill, font, 
	
	html labels, table features, anchor features, font features

	polylines, splines: pen styles, parallel edges

	arrow shapes

Layout tests:

	node sizing around labels, html labels

	user-shapes: sizing and format detection

	node and edge positions

	edge labels: main, head, tail

	rankdir

	clusters

	mincross

	splines

Format-specific tests:

	anchors
		maps, ps, svg
	
	paging, layering, multigraphs, 
		ps

	zoom, size, dpi, margin
		png, svg, ps, maps

	colors: known colors, pen and fill combinations, transparency, color indexing
		png, ps, svg

	user-shapes: image loading, input/output format transforms, multiple instances
		

Perfomance tests:
	
	some benchmark test so that we can catch gross perfomance changes
		layout
		renderer
		plugin loading

Platform tests:

	some tests that exercise platform features:
		32 v 64 bit
		byte ordering
		toolchain variations: compiler, linker, lex, yacc, ...
		floating-point variations
