[FIXED HUDSON-3482] release date is added to the changelog automatically

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@24774 71c3de6d-444a-0410-be80-ed276b4c234a

update.changelog.rb

@@ -48,7 +48,7 @@ id.inc()
 ARGF.each do |line|
   if /=BEGIN=/ =~ line
     puts line
-    puts "<h3><a name=v#{id}>What's new in #{id}</a></h3>"
+    puts "<h3><a name=v#{id}>What's new in #{id}</a> <!--=DATE=--></h3>"
     puts "<!--=RC-CHANGES=-->"
     puts "</div><!--=END=-->"
 
@@ -57,5 +57,9 @@ ARGF.each do |line|
   if /=END=/ =~ line
     next
   end
+  if /=DATE=/ =~ line
+    puts line.gsub("<!--=DATE=-->",Time.now.strftime("(%Y/%m/%d)"))
+    next
+  end
   puts line
 end