Ability to exclude URLs from a sitemap

Adds the ability to exclude a URL for being added to a sitemap (very common need).

sitemap/sitemap.py

@@ -161,9 +161,13 @@ class SitemapGenerator(object):
             chfreq = self.changefreqs['indexes']
 
         pageurl = '' if page.url == 'index.html' else page.url
+        
+        #Exclude URLs from the sitemap:
+        sitemapExclude = []
 
         if self.format == 'xml':
-            fd.write(XML_URL.format(self.siteurl, pageurl, lastmod, chfreq, pri))
+            if pageurl not in sitemapExclude:
+                fd.write(XML_URL.format(self.siteurl, pageurl, lastmod, chfreq, pri))
         else:
             fd.write(self.siteurl + '/' + pageurl + '\n')