Created test to prove issue

USERGRID-1861
Initial refactor of IR to have OrderByIterators.  SliceScanners will
need to return the full column before this can be finished.

USERGRID-1861
Poke to fix slf4j-api missing from compile dependencies.
Poke to fix slf4j-api missing from compile dependencies.
Updated order by visitor to handle single slice iterator vs order by iterator.  Need to add multiget and specific props to the EM to make sort loading faster.

USERGRID-1861
Updated to perform sorting per primary iterator page.

USERGRID-1861
The load works.  However, there are issues with cursors and paging

USERGRID-1861
The cursor is highly inefficient.  We're re-visiting nodes that we've already dropped on subsequent cursor invocations.  Need to optimize this better.

USERGRID-1861
Fixes iterators with single order by field

USERGRID-1861
Merge remote-tracking branch 'origin/master' into USERGRID-1861-2

Conflicts:
	core/src/main/java/org/usergrid/persistence/Query.java
	core/src/main/java/org/usergrid/persistence/cassandra/EntityManagerImpl.java
	core/src/main/java/org/usergrid/persistence/cassandra/QueryProcessor.java
	core/src/main/java/org/usergrid/persistence/cassandra/RelationManagerImpl.java
	core/src/main/java/org/usergrid/persistence/query/ir/NodeVisitor.java
	core/src/main/java/org/usergrid/persistence/query/ir/SearchVisitor.java
	core/src/test/java/org/usergrid/persistence/query/AbstractIteratingQueryIT.java
	services/pom.xml
Merge branch 'USERGRID-1861' of https://github.com/apigee/usergrid-stack into USERGRID-1861
Refactored tests to clean up

USERGRID-1861
Refactored tests to clean up

USERGRID-1861
Merge branch 'USERGRID-1861' of https://github.com/apigee/usergrid-stack into USERGRID-1861
Fixing issue with not running some tests.
Updated tests, test multi ordering with complex candidate results.

USERGRID-1681
Merge branch 'USERGRID-1861' of github.com:apigee/usergrid-stack into USERGRID-1861
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
Fixing various build issues due to double execution by Maven
surefire.
fix compilation error due to deleted file