Fix composite comparator with super columns

patch by slebresne; reviewed by thobbs for CASSANDRA-5287
Merge branch 'cassandra-1.2' into trunk

Conflicts:
	src/java/org/apache/cassandra/config/CFMetaData.java
avoid allocating unused HashMap for RowMutation
Merge branch 'cassandra-1.2' into trunk
special-case single-CF mutations to deserialize to singletonMap instead of HashMap
add single-CF specialization of RowMutation constructor
convert RowMutations on the cql3 path to use more-efficient mutations map
add TODO for builder conversion
convert internal_insert to use more-efficient RowMutation constructor
OutboundTcpConnection class retrieves local IP
patch by Marcus Eriksson; reviewed by Vijay for CASSANDRA-5299
Merge branch 'cassandra-1.2' into trunk
Fix insufficient validation of UPDATE queries against counter cfs

patch by slebresne; reviewed by iamaleksey for CASSANDRA-5300
Merge branch 'cassandra-1.2' into trunk
Fix propertyFileSnitch default DC/Rack behavior

patch by slebresne; reviewed by jbellis for CASSANDRA-5285
Merge branch 'cassandra-1.2' into trunk
cqlsh: Ninja-alter blob formatter (prepend '0x')
Merge branch 'cassandra-1.2' into trunk
dsnitch severity is not correctly set for compaction info
patch by Vijay; reviewed by jbellis for CASSANDRA-5255
Merge branch 'cassandra-1.2' into trunk
more descriptive exception message