Instiki 0.16.5

Update to Rails 2.3.2 (the stable Rails 2.3 release).
Add audio/speex support
Update CHANGELOG
Bump version number

vendor/rails/actionmailer/lib/action_mailer/base.rb

@@ -479,7 +479,7 @@ module ActionMailer #:nodoc:
             )
           end
           unless @parts.empty?
-            @content_type = "multipart/alternative"
+            @content_type = "multipart/alternative" if @content_type !~ /^multipart/
             @parts = sort_parts(@parts, @implicit_parts_order)
           end
         end