Add KeyCacheHitRate metric to CF metrics

patch by yukim; reviewed by jbellis for CASSANDRA-5868
Merge branch 'cassandra-1.2' into cassandra-2.0.0

Conflicts:
	CHANGES.txt
	src/java/org/apache/cassandra/io/sstable/SSTableReader.java
	src/java/org/apache/cassandra/metrics/ColumnFamilyMetrics.java
	src/java/org/apache/cassandra/service/CacheService.java
Merge branch 'cassandra-2.0.0' into cassandra-2.0
migrate 1.1 schema_columnfamilies.key_alias column to key_aliases
patch by Alex Liu; reviewed by Tyler Hobbs for CASSANDRA-5800
Merge branch 'cassandra-1.2' into cassandra-2.0.0
Merge branch 'cassandra-2.0.0' into cassandra-2.0
Correct timestamp formatting in CQL3 doc
Merge branch 'cassandra-1.2' into cassandra-2.0.0
Merge branch 'cassandra-2.0.0' into cassandra-2.0
enable vnodes by default (CASSANDRA-5869)
patch by jbellis; reviewed by brandonwilliams for CASSANDRA-5869
merge from 2.0.0
Remove the vestiges of default_{read,write}_consistency
Merge branch 'cassandra-1.2' into cassandra-2.0.0

Conflicts:
	src/java/org/apache/cassandra/config/CFMetaData.java
Merge branch 'cassandra-2.0.0' into cassandra-2.0
Fix (some) 2i on composite components omissions

patch by Aleksey Yeschenko; reviewed by Jonathan Ellis for
CASSANDRA-5851
Merge branch 'cassandra-2.0.0' into cassandra-2.0
cqlsh: add DESCRIBE FULL SCHEMA variant

patch by Aleksey Yeschenko; reviewed by Jonathan Ellis for
CASSANDRA-5880
Merge branch 'cassandra-2.0.0' into cassandra-2.0
Improve JMX support for streaming

patch by yukim; reviewed by thobbs for CASSANDRA-5859
suppress sending too many progress notifications