Changes to jmx.java

Few minor changes to make it easier to work with Hbase 0.94.9

1. Support for Composite data types. This allows to collect heap stats from Memory bean
2. mbsc.getAttribute(object, name) was raising exception " java.lang.UnsupportedOperationException: CollectionUsage threshold is not supported" for some attributes
3. Ignore string and boolean values as they have no value for OpenTSDB

Still need to make some changes to Hbase collector to reduce spam, I'll check that in once I clean it up. 

Limus