Remove MySQL specific code from site generation code

- site-generator is generic, so no changes.
 - removed mysql information from site.cfg.
 - Updated template files to call sqlite queries directly.
 - Renamed the query files - remove sqlite from file names.
 - Deleted MySQL specific template files.

templates/rss-comments.tpl.xml

@@ -24,7 +24,7 @@
     <width>144</width>
   </image>
   <atom:link href="<!--% absolute_url(http_baseurl) %-->comments.rss" rel="self" type="application/rss+xml" />  
-  <!--% USE DBI(constants.driver, constants.user, constants.password) %-->
+  <!--% USE DBI(constants.driver) %-->
   <!--% FOREACH response IN DBI.query('SELECT max( comment_timestamp) AS latest_update FROM comments') %-->
   
   <pubDate><!--% format_feed_date(response.latest_update) %--></pubDate>