csplit: add the --suppress-matched option
With --suppress-matched, the lines that match the pattern will not be
printed in the output files. I.E. the first line from the second
and subsequent splits will be suppressed.
* src/csplit.c: process_regexp(),process_line_count(): Don't output the
matched lines. Since csplit includes "up to but not including" matched
lines in each split, the first line (in the next group) is the matched
line - so just skip it.
main(): Handle new option.
usage(): Mention new option.
* doc/coreutils.texi (csplit invocation): Mention new option, examples.
* tests/misc/csplit-suppress-matched.pl: New test script.
* tests/local.mk: Reference the new test.
* NEWS: Mention new feature.