Issue #57: Add attribute history documentation.
Issue #57: Add attribute history documentation.

mk23/jmxproxy,mk23/jmxproxy-test,mk23/jmxproxy,mk23/jmxproxy-test,mk23/jmxproxy,mk23/jmxproxy-test,mk23/jmxproxy,mk23/jmxproxy,mk23/jmxproxy,mk23/jmxproxy-test,mk23/jmxproxy-test,mk23/jmxproxy-test