Adjust documentation for variable substitutions.  Many but
not all of the substitutions are listed in the "variables" help
file.  The error_files, format_files, and reply_files help files
list the files that support variable substitutions.

Add help files for the wwwadm_url and wwwusr_url GLOBAL settings.

Add the admin_domain help file, which explains in detail how the
GLOBAL and DEFAULT lists are used within the context of a domain.
Flesh out digest and nomail details.
(standard_subs) Add CONFIRM_URL, WWWADM_URL and WWWUSR_URL variables
to the standard substitutions.  These give the values from the GLOBAL
configuration settings of the same names (wwwadm_url and wwwusr_url are
new settings).

(help_start)  Use "help overview" as the default help page;
"help help" instead displays a summary of the help command.

(_faq, _info, _intro)  Allow LASTCHANGE substitution to be used
to supply the date on which the document was last modified.
Add entries for the GLOBAL wwwadm_url and wwwusr_url settings.
(list_access_check, _a_mailfile)  Make reply, replyfile, and mailfile
substitutions consistent with one another.
Treat the master_password access rule variable as a number, not a string.
(parse_table)  Strip leading and trailing white space from the table data.
(getdata)  Include the time of last modification in the file data.
(report)  Break out statistics by list when the ALL list is specified.
Include mean time required for each command to be executed.
Substitute appropriate values for the wwwadm_url and wwwusr_url
default settings during installation (the domain is not included,
to allow extended path information to be used with the variable
substitutions.
Add DOMAIN substitution.
Account for carriage returns in form data.
(parse_part)  Inform about "parse" failure if no valid commands were found.
  This was inspired by a recent autoresponder loop, for which no activity
  was logged because of the absence of valid commands in each message to
  majordomo.
(sessioninfo_done)  Add missing routine, without which the sessioninfo
command does not finish.
(parse_pw) Do not log the password.
(_make_fs) Do not use the filedir setting, due to potential security
issues.
Remove files for the filedir configuration setting.
Move the output of the mj_confirm interface into format files.
Warn that a setting used in the configset or configdef commands is
not supported by Majordomo.
Rewrite to use format files.