Clone partition key for ReadCommands to avoid netty corruption

patch by jake; reviewed by jason brown for CASSANDRA-7465
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
ninja fix: raise default concurrent compactors to 4 to avoid LCS test timeout
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
ninja: Always make a copy in BBU.getArray()
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Fix compilation with java 6 (JAVA-7147 regression)
Changelog
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	CHANGES.txt
	src/java/org/apache/cassandra/utils/ByteBufferUtil.java
Merge branch 'cassandra-2.0' into cassandra-2.1.0

Conflicts:
	CHANGES.txt
Merge branch 'cassandra-2.1.0' of https://git-wip-us.apache.org/repos/asf/cassandra into cassandra-2.1.0
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Fix CommitLogTest