Merge from vendor branch TNF:

Merge from vendor branch TNF:
Initial import of gutcheck-0.991:

Gutcheck is a plain-text checking program that specializes in
reporting the problems that spellcheckers don't--errors like
mismatched quotes, misplaced punctuation, unintended blank lines.
It is specifically tuned for checking texts for submission to
Project Gutenberg, though it can be useful elsewhere as well.