* Support @mnot's IETF Comments Markdown Format

* More Markdown

* Reduce false positives when matching IP addresses

* Don't quote context when outputting Markdown

* Pluralize (more) correctly.

* Handle empty contexts

* Remove spurious print

* Suppress more likely false positives

* Fix Markdown

* Don't warn about unparsable IP addresses unless running verbosely

* Small fix to doc position tracking