(get_entity_structure, remove_part, replace_part)
  New routines.  Given a file containing a message, obtain or alter the
  structure of the message.  Each part within a message is given a number:
  "1" for the top-level part, "1h" for its headers, "1.3" for the third
  subpart, "1.3.2" for the second subpart of the third subpart, and so on.
Remove references to the tokeninfo-full command.
Reformat paragraphs.
Correct typos and improve the description of the minage field.
Add descriptions of the new incompatible_mode and missing_mode error
files, which warn that command modes are incompatible, or that a
required mode is missing.
Describe the support files for the new tokeninfo-part commands.
Describe the new tokeninfo-part commands.
Describe a few more substitution variables.
Include a description of the "pattern" command mode.
Add error files for stricter mode checking.
Minor formatting adjustments.
Remove redundant date and author information.
Bugfix:  only add "immediate" mode to the archive command if
the "get" mode is also present.
Correct typo.
Moderators, not owner.
Add $addrcomment access variable, containing the comments parsed from the
victim address.
Add access variables containing various post-related statistics.
Use a Yes/No menu for boolean configuration settings, as suggested
by Gavin Walker.
Include some ideas discussed recently on mj2-dev.
Document the configshow_bool file.