Fix TokenMetadataTest
remove unnecessary(and failing) test
Fix ScrubTest
Fix LeaveAndBootstrapTest
Fix potential ConcurrentModificationException in tests
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	test/unit/org/apache/cassandra/db/ScrubTest.java
	test/unit/org/apache/cassandra/service/LeaveAndBootstrapTest.java