Remove reference to deleted htmlmail_admin_settings_submit(); properly set defaults for header and footer.

Theme template file is now applied even if an output theme is also selected.

* Allows using either template files or a full Drupal theme to format emails.
* Allows both a pre-theme and a post-theme text format filter to be applied.
* Sends emails as Multipart/Alternative with text/plain and text/html parts.
* Adds a "Plaintext only" profile field for users who prefer plaintext emails.
* Relies on the new "Mail System" module for setting the mail_system variable.

To Do:
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* Move emogrifier and transliteration to separate filter modules.
* Rewrite module_requirements() and info file accordingly.
* Update README.txt to explain about the format filter change.

Note:
-----

The HTML-to-plaintext conversion relies on drupal_html_to_text which is
currently broken by "Patch #356074".  A fix is posted in the issue queue.

@see http://drupal.org/project/mailsystem
@see http://drupal.org/node/900794
@see http://api.drupal.org/api/drupal/includes--mail.inc/interface/MailSystemInterface/7
@see http://api.drupal.org/api/drupal/includes--mail.inc/function/drupal_html_to_text/7
@see http://drupal.org/node/299138
@see http://drupalcode.org/viewvc/drupal/drupal/includes/mail.inc?r1=1.25&r2=1.26
@see http://drupal.org/node/299138#comment-4193400

todo add core token functions

hook_theme changes are interesting
still much to do

still messy and broken

formatting changes

add theme functions so templates can be selected from a chosen path relative to the theme -- for future email campaign templates

change htmlmail.tpl.php layout to tables --  no, tables aren't back. just we still have to rely on old, old-fashioned tables for compatibility

NOTES! :(

- add @file block, as per formatting conventions

My understanding is that MIT license is compatible with Drupal if existing licensing is kept intact?? I see other modules include this class so i'm assuming it's ok.