Currently the hbase-site.xml configuration is hardcoded in the configure(_cdh)_hbase.sh script. This patch adds dynamic generation of hbase-site.xml, modelled after what is done for hadoop-(common|mapred|hdfs)-site.xml.
The user is able to specify custom properties in their cluster configuration, by prefixing them with 'hbase-site.'
Default config is in whirr-hbase-default.properties. Compared to what was in configure_hbase.sh before, I dropped the setting of "hbase-site.hbase.client.retries.number=100" because I'm not sure we should divert from the HBase default there.
I left in the passing of the ZOOKEEPER_QUORUM to the configure script, as I figured people using custom scripts might still want to have it (there's a PORT variable passed that doesn't seem to be used either).
On a more general note, this patch has the same limitations as for Hadoop: running master and regionserver on same node will not work as the configuration will be appended twice to the same file, and running the restserver/thriftserver not together with regionserver or master will fail due to missing hbase-site.xml. Solving this is a topic of its own.