HZ-11: Fire the left cluster event before we leave the cluster

closes #1030

When displaying the details of a certificate, the admin console now also shows
its PEM representation. This is convenient for copy/pasting the certificate into
other tools.

OF-1494: Fix the xmppAddr SAN othername entry in generated certs.

was missed for maven builds previous to 4.2.2 release

Handling xmppAddr being a type of ASN1TaggedObject (i.e. DERTaggedObject) as it fails to cast the xmppAddr to ASN1String to work with CA signed certificates/self-signed certificates generated with OpenSSL.

* OF-1482: Monitoring plugin: MUC MAM responses should have a 'from'.

* OF-1483: Monitoring plugin: restore admin console functionality.

* OF-1455: Allow for bulk property migration.

* OF-1454: New Property-based Provider Mappers.

HZ-8: Preserve Hazelcast network settings between plugin upgrades

HZ-5: Ensure themarkedAsSeniorClusterMember event is fired

npe.

So the full stack trace can be displayed. I also fixed the typo (Unkown -> Unknown).

* Sending message body inside of callback

* Updated version and readme.html

* Updated changelog

* Sending POST request. Better logs. sendBody property.

* Updated readme and changelog. v1.2

* Fixed small bug

OF-891: Ensure that the clusteringStarting/clusteringStarted flags ar…

OF-1475: Update to Hazelcast 3.9.2.

OF-1472: Add basic support for XEP-0157.

OF-1471: Terminate upon invalid Stream Management data.

Allow remotely connected servers to subscribe to local pubsub nodes

OF-1469 New plugin: XEP-0215 External Service Discovery

OF-891: Ensure that the clusteringStarting/clusteringStarted flags are correctly set when clustering starts.