* Check completeness of "junk" line handling.
* Known issue: junk lines not processed inside "Comments" blocks. Need to add
a parameter containing things-that-are-not-junk to parse_comments.
* Resync with spec
* Handle \# in test descriptions, when the spec is updated for it
* Spaces between # and directive, and directive and reason, should be optional
* Clarify handling of unknown directives
* Comprehensive test suite.