Review and complete remaining commands

Polishing. Review each command and put a + next to each as it is fully done.

Top level:

  ADD       +BACK       BULLETIN   CHANGE     COPY       CREATE
 +Ctrl-C    +CURRENT    DELETE     DIRECTORY +EXIT      +FIRST
 +Folders    FORWARD   +HELP       INDEX     +Keypad    +LAST
  MAIL      +MARK      +MODIFY     MOVE      +NEXT      +PRINT
 +QUIT      +READ       REMOVE    +REPLY      RESPOND   +SEARCH
  SEEN       SELECT    +SET       +SHOW      +SSH       +UNMARK
  UNSEEN    +USER

SET:

 +ACCESS          +ALWAYS           BRIEF            DEFAULT_EXPIRE
  EXPIRE_LIMIT     FOLDER          +NOACCESS        +NOALWAYS
  NOBRIEF          NOPROMPT_EXPIRE  NOREADNEW        NOSHOWNEW
  NOSYSTEM         PROMPT_EXPIRE    READNEW          SHOWNEW
  SYSTEM

SHOW:

 +FLAGS       FOLDER     -NEW        +PRIVILEGES  USER       +VERSION

SSH:

 +ADD       +DELETE    +FETCH     +LIST

USER:

 +ADD       +ADMIN     +DELETE    +DISABLE   +ENABLE     LIST
 +MOD       +NAME      +NOADMIN   +NOMOD