#1473: Add JMX support.

This is a first attempt on adding jmx support to jclouds and I am creating a pull request for feedback.

What this pull request adds:

i) A Management Context, which keeps tracks of jclouds managed beans, contexts and mbean servers.
ii) Converter functions for converting objects to open types (So that the jclouds mbeans can be used from jconsole, visualvm without requiring the addition of jclouds client jars).
iii) Annoatations that mark which classes are convertible to open types and how they should be converted.
iv) Mbeans for displaying Apis, Providers and Contexts. Also MBeans for compute services and blobstores.