Now that -c behaves correctly, the tools are pretty much done.
Only the manpages were not clear enough what happens when you
specify the c-flag.
This is fixed now.
*sum tools: -c was added
tr: -d flag was added.
xargs: -n flag was added.
cmp: minor typo (change to lowercase).
Signed-off-by: Hiltjo Posthuma <hiltjo@codemadness.org>