Settings - Outbound Mail uses localhost as HELO name for SMTP

When saving and sending a test email from the outbound mail configuration page Civi uses "localhost" as the SMTP HELO name. Some mail relay agents reject this host name when connected to remotely. When sending a real email from Civi (such as when emailing a contact) the web server hostname for the Civi site seems to be correctly used as the HELO host name and causes less problems for MTA's.

Similar issue to http://issues.civicrm.org/jira/browse/CRM-3153 but it seems that here the Test Email from the Outbound Mail settings page is not consistent with the rest of the system when setting the HELO host name.