reduce default diff-box recursion depth from 1024 to 32

rename 'debug.h' to 'diff_debug.h'

add support for ignoring whitespace (-w option) Tests grow the ability to call diff with options. Options to use are encoded in the test file name as a single dash followed by a string of option letters. E.g. -wp for 'ignore whitespace' and 'do patience'

diff result: ensure sane order of result chunks Ensure that a adjacent chunks of same type are combined, and that a minus block always precedes an adjacent plus block. The upcoming myers-divide optimization is prone to produce weird ordering of plus and minus chunks.

add diff_atom_cmp() and error handling to diff_atom_same()

avoid include statements in header files; make each .c pull in what's needed

replace enum diff_rc errors with plain errno values

fall back on file i/o in case an input file cannot be memory-mapped

KNF: use max 80 columns

KNF: function declaration return types on separate line

debug: myers graph dump tweaks In debug output: fix some indents, fix printing of max state size, in myers graph, limit x axis labels to 2 digits, print colored markers of current myers graph positions, also print myers-divide positions in myers graph.

initial commit