Add check if ANDROID_HOME is set to build.gradle
Use CopyOnWriteArraySet in InvitationsMonitor
Use from(Packet) instead of getFrom(Packet) in DeliveryReceiptManager
Add Packet to onReceiptReceived parameters

in ReceiptReceivedListener. SMACK-582
Use CopyOnWriteArraySet in DeliveryReceiptManager
Add DeliveryReceiptRequest.addTo(Message)
Add message String to all SmackExceptions

SMACK-599