FBUtilities.singleton() should use the CF comparator

patch by slebresne; reviewed by thobbs for CASSANDRA-6778
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
	src/java/org/apache/cassandra/cql3/statements/ColumnGroupMap.java
	src/java/org/apache/cassandra/cql3/statements/SelectStatement.java
	src/java/org/apache/cassandra/db/SystemKeyspace.java
	src/java/org/apache/cassandra/db/filter/NamesQueryFilter.java
	src/java/org/apache/cassandra/utils/FBUtilities.java
	test/long/org/apache/cassandra/db/LongKeyspaceTest.java
	test/unit/org/apache/cassandra/SchemaLoader.java
	test/unit/org/apache/cassandra/config/DefsTest.java
	test/unit/org/apache/cassandra/db/CollationControllerTest.java
	test/unit/org/apache/cassandra/db/ColumnFamilyStoreTest.java
	test/unit/org/apache/cassandra/db/KeyspaceTest.java
	test/unit/org/apache/cassandra/db/ReadMessageTest.java
	test/unit/org/apache/cassandra/db/RecoveryManagerTruncateTest.java
	test/unit/org/apache/cassandra/db/RemoveCellTest.java
	test/unit/org/apache/cassandra/io/sstable/LegacySSTableTest.java
	test/unit/org/apache/cassandra/tools/SSTableExportTest.java
Fix CQLSSTableWriter.addRow(Map<String, Object>)

patch by slebresne; reviewed by thobbs for CASSANDRA-6526
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
Fix timestamp scaling issue for 6623
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	src/java/org/apache/cassandra/cql3/statements/ModificationStatement.java
Fix comment post-merge