Better textfields and CMS upgrades

some special feature enhancements for ad-hoc CMS use:

    * Model value uses a text field instead of a char 255 field, for larger content storage
    * Enhanced TextValue to use a text area widget
    * Added TinyMCE support. If django-tinymce is installed, an HTMLValue field will show a TinyMCE form, otherwise defaults to a text area
    * Many improvements to Admin UI, better presentation of Groups, form field styling table layout fixes