PHPDocumentor [http://en.wikipedia.org/wiki/PhpDocumentor] documentation tweaking...

PHPDocumentor [en.wikipedia.org/wiki/PhpDocumentor] documentation tweaking stuff.

Minor doc tweaks to prevent some PHPDocumentor warnings or errors when run on the includes/ directory. PHPDocumentor uses a syntax very similar to javadoc - mostly we already use this, but there were a few scattered places that were adjusted to make them consistent with the rest of the code. In practical terms, these changes were made:
* @url becomes @link
* @fixme becomes @todo
* HTML tags in descriptions must be closed / balanced.
* @bug was removed (where the bug was long fixed), or changed into a @todo (in the few situations where the bug was still pending)
* @obsolete becomes @deprecated
* Things like "/**@{{" and "/**@}}*/" which cause "unknown tag" warnings were removed
* @access must be a valid access level.
* @desc tag not needed, removed.
* Doesn't seem to like @licence, will accept @license however.
* Use full comment block notation in a few places (i.e. open block with "/**", start each line with " *", and end block with " */")

Then additional to this, to get some class docs associated with their respective classes:
* Moved some docs to right above those classes (deleting blank lines, or moving descriptions from the file headers)
* Marked some classes without docs as "@todo document"
* (done up to "class MIMEsearchPage" on the "classtrees_MediaWiki.html" page for the includes/ directory)