Smack 4.0.0-rc3-SNAPSHOT
Do not filter groupchat messages without body

for MessageListeners in MultiUserChat

SMACK-568
Fix lost sharedManfiest configuration in build.xml

The configuration of ext.sharedManifest was no longer included (since
39c837190df002fad90be61f22c7ecadc072e263).
Make getMulitipleRecipientServiceAddress() more robust

the method should not throw if one of server's items fail to query.
Improve getMultipleRecipientServiceAddress

and MultipleRecipient (XEP-33) related code in general (e.g. use
constants where possible).

For getMultipleRecipientServiceAddress() this means that
- the "synchronized (services)" block is removed
- ServiceDiscoveryManager is only retrieved once
Add missing mechanism-too-weak SASL Error
Change IQ.Type to enum
Smack 4.0.0
Merge branch '4.0'

Conflicts:
	build.gradle
	smack-extensions/src/main/java/org/jivesoftware/smackx/muc/MultiUserChat.java
Fix MessageTypeFilter.ERROR

s/Type.headline/Type.error/
Streamline String to Enum transformation

for the core stanza Enums.
Throw more exceptions when parsing Presences

when parsing core elements of Presences.
Add PacketExtensionFilter(PacketExtension) constructor

and PacketExtensionFilter(Class<? extends PacketExtension).
Use new PacketExtensionFilter constructor

in OfflineMessageManager
MessageEventManager's PacketFilter should ignore error type messages

Fixes SMACK-573