Changeset discussions

Add support for commenting on changesets with RSS feeds and email
notification of comments to other commenters and people that have
chosen to subscribe to a changeset.

app/views/changeset/comments_feed.rss.builder

@@ -0,0 +1,14 @@
+xml.rss("version" => "2.0", 
+        "xmlns:dc" => "http://purl.org/dc/elements/1.1/") do
+  xml.channel do
+    if @changeset
+      xml.title t('changeset.rss.title_particular', :changeset_id => @changeset.id)
+    else
+      xml.title t('changeset.rss.title_all')
+    end
+    xml.link url_for(:controller => "site", :action => "index", :only_path => false)
+
+    xml << render(:partial => "comments", :object => @comments)
+
+  end
+end