                          Pod::Thread To-Do List

Output:

 * Adding headings to the table of contents or navbar while bypassing all
   of the parsing causes problems when they contain formatting codes.
   Instead, figure out how to splice the POD for those elements into the
   document so that they can be parsed.  (Sadly, this will probably
   require some sort of custom POD command, since POD can't replicate the
   necessary formatting.)

Test suite:

 * Add basic tests for at least all of the basic thread commands that the
   module may output.

 * Add tests for the various constructor options.
