don't use o.a.commons.io for one method
Merge branch 'cassandra-2.1' into trunk
return all cpu values from BackgroundActivityMonitor.readAndCompute

patch by dbrosius reviewed by jbellis for cassandra-7183
Merge branch 'cassandra-2.0' into cassandra-2.1
make sure manifest's parent dirs exist before trying to write the file.
Merge branch 'cassandra-2.1' into trunk