Notes:
This is a maintenance release for Z-Push 1.5.

It is recommended for Zarafa systems with a hundred or more Z-Push users and/or having a high load caused by apache.
Also the ping interval was increased to 30 seconds by default.


Changes:
General
- changed: Increase ping timeout by default (Mantis #536)
- fixed: New mail from android produces @localhost error in spooler and postfix logs. Do not parse an email address if it is set but empty. (Mantis #554)
- fixed: break while in PING case unknown tags are sent (Mantis #538)

Zarafa/ICS
- partly undone rev 775, as a conflict detection for read flags is not really necessary and may result in timeouts (Mantis #537)
- fixed: PHP Warning: Call-time pass-by-reference has been deprecated. It was deprecated in PHP 5.3 (Mantis #552)