Tokens issues [#1891374]

Added tokens for all date formats, using format_date() so that translation can occur.
Changed the 'workflow-current-state-date-formatted' token to use the site's default date format.
The 'workflow-current-state-date-iso' token was not actually ISO format.
Added a token for a link to the user's account.
Added a token to link to the user's email.
Changed 'workflow-current-state-updating-user-name' to use format_username() so any name alteration
modules (e.g. RealName) can get involved.
Changed 'workflow-current-state-log-entry' to use check_markup() with the site's default input format.
The filter_xss() list was not terribly inclusive.
(We might want to add a setting sometime to choose a different one.)
Looking at http://api.drupal.org/api/drupal/modules!system!system.api.php/function/..., it seems that
we should not be returning all token values, but rather only those requested in the second calling parameter.
As an example, see http://api.drupal.org/api/drupal/modules!system!system.tokens.inc/functi....
This does not seem to be a serious issue now, but there's no telling about the future.