Initial commit to make reads work with an iterator style read

USERGRID-1161
USERGRID-1390
Conflicts:
	core/src/main/java/org/usergrid/persistence/cassandra/CassandraService.java
Cleaned up existing operations before updating the merge operations.

USERGRID-1046
Conflicts:
	core/src/main/java/org/usergrid/persistence/cassandra/CassandraService.java
	core/src/test/java/org/usergrid/persistence/CollectionTest.java