added colour coding to unified diff
Used ANSI escape sequences as in http://stackoverflow.com/questions/287871/print-in-terminal-with-colors-using-python to add colour-coding to src diff -u.
No colour coding yet for src diff -c.
Used ANSI escape sequences as in http://stackoverflow.com/questions/287871/print-in-terminal-with-colors-using-python to add colour-coding to src diff -u.
No colour coding yet for src diff -c.