The summary XHTML form selects either up to the first two paragraphs
it find in a page or the first section (whichever comes first)
It strips out the table of contents if one exists
Section divs are not used - everything should be nested in a single
div with CSS class "page"
Headings have their a name link removed and section editing links
It also attempts to capture the first heading in a page for
use as the title of the page.