Updated rails to 2.3.17.
Temporairly deactivated ruby spec in Gemfile.

Background. Our bundler is too old on the production server and
I don't want to break other applications.
Damn'it. Forget to update environment file after rails update.
Comment out rake/rdoctask due to rake update.
Installed rdoc to avoid messages in rake tasks.
Fixed missing recipients when Message.send_emails.
Avoid sending mails twice via concurrent background processes.
Also validate article price attributes.

Fixed adding articles with unit_quantity = 0, what causes an error in ordering page. Fixed #86
Fixed bug when submitting huge forms. (stock taking etc)