Add css and prettify. Make RecentChanges use table for
formatting, and images to indicate web vs svn commits and to link to diffs.

All of this should be doable w/o touching a single line of code, just
editing the [[templates]] BTW.

## html validation

  * A doctype should be added: do we want XHTML 1.0 or HTML 4.01 Trans as
    default?
    
	Need to choose a doctype that corresponds to what [[MarkDown]]
	generates. For example, it does generate <hr />
	So xhtml seems a good fit and I'm going to add that to the
	templates. 
	
	One consideration of course is that regular users might embed html
	that uses deprecated presentational elements like <center>. At
        least firefox seems to handle that mixture ok. 
	--[[Joey]]
	
  * If XHTML: In templates <hr> should become <hr /> etc.
        
    Done --[[Joey]]

  * Image wikilinks should provide an alt text (maybe '$filname wiki-image'?).

  	Now it will be the text of the [[WikiLink]], which even allows
	setting a custom alt text like this: \[[my_alt_text|image.png]]
	--[[Joey]]
	
  * &'s in (cgi-)url's must be escaped as &.
  
  	Fixed --[[Joey]]
	
  * [ [inlinepage] ] gets wrapped in <p>...</p> which has a high chance of invalidating the page.

  	Since markdown does this, the only way I can think to fix it is to
	make the inlined page text start with </p> and end with
	<p>. Ugly, and of course there could be problems with
	markdown enclosing it in other spanning tags in some cases.
	I've implemented this hack now. :-/ --[[Joey]]

  * This page is now valid, although the validator conplains at having to guess the encoding. Should the encoding be forced to utf-8 in the templates?

Test: [validate this page](http://validator.w3.org/check?url=referer)