Fix numerous HTML errors from W3C validator

* confusion about nesting of p and ul/ol/pre/blockquote elements
* confusion about nesting of a and h1 elements
* some dangling close tags
* replaced some silly uses of <br/> with p elements
Minor English fixes.

 * fix bad spelling
 * use American spellings (e.g. analyze vs analyse)
 * don't introduce artificial sentence breaks for "i.e." and "e.g."
 * use the definite and indefinite articles more appropriately
 * various other minor grammar fixes
 * remove one copy of a duplicated paragraph
Fix some more errors from the W3C validator

 * un-escaped use of < and > in a 'pre' element
 * confusion about nesting of p and ul/ol/pre/blockquote elements
 * confusion about nesting of li and ul elements
 * added p elements around completely naked text
 * escaped naked < > and & characters
 * removed dangling </li> </div> and </h4> tags
 * clean up weird auto-generated HTML
	- paragraph boundary weirdness
	- a display div was being used where a <dl> was best
 * removed unnecessary whitespace
 * changed a pre element which was apparently intended to be inline
   to a tt element which is actually inline not block.
HTML-ise old admin tool description

Manually convert description of the old admin tool from automatically
converted text to some semblance of HTML
More minor English fixes.

 * fix bad spelling, poor capitalization, and lost spaces
 * various other minor grammar fixes
 * correct plural of "synopsis"
Fix indentation of example XML
Remove spurious li element end