added hasOutstandingTransactions() and hasMessagesInQueue() methods
ensure Query is serializable w/ Identifiers
access to QueueManager
Updated calls to accurately check for messages.

USERGRID-1768
Merge branch 'master' into USERGRID-1768
proper query serialization
fix Query by Identifier
access to properties through ServiceManager
Merge branch 'master' into USERGRID-1768
Merge pull request #188 from apigee/USERGRID-1768

Usergrid 1768
Merge remote-tracking branch 'origin/master' into USERGRID-1861

Conflicts:
	core/src/test/java/org/usergrid/mq/MessagesIT.java
	mongo-emulator/src/test/java/org/usergrid/mongo/AbstractMongoTest.java