HBASE-12455 Add 'description' to bean and attribute output when you do /jmx?description=true

Conflicts:
	hbase-server/src/main/java/org/apache/hadoop/hbase/http/jmx/JMXJsonServlet.java
	src/main/docbkx/ops_mgt.xml
HBASE-12447 Add support for setTimeRange for RowCounter and CellCounter

Signed-off-by: stack <stack@apache.org>