Add EAS as an option, but mark it experimental for now.

Features that clients have implemented are completed.

No current client has implemented the event attachments or draft email
sync sync yet. Those will be implemented/tested when that occurs.

horde/config/conf.xml

@@ -2253,6 +2253,7 @@
        <value desc="Exchange 2007sp1 (EAS 12.1)">12.1</value>
        <value desc="Exchange 2010sp1 (EAS 14.0)">14</value>
        <value desc="Exchange 2010sp2 (EAS 14.1)">14.1</value>
+       <value desc="Exchange 2013 (EAS 16.0) EXPERIMENTAL">16.0</value>
       </values>
      </configenum>
      <configheader>Authentication</configheader>