Expose CacheView string via JMX

The JGroups view and CacheView differs and this causes trouble finding out what state the CacheView is in during elasticity/reslience tests.

My test controller is driven by JGroups view, there was this particular case where this lead to test failure, or better said wrongly controlled test.

After node0002 was killed in view 7:
http://www.qa.jboss.com/~mlinhard/hyperion/run53-elas-dist-basic/table.html

the controller saw JGroups view: [node0003/default|5] [node0003/default, node0004/default]
which maybe existed in JGroups layer but never in Infinispan - in infinispan there was partition

+

and therefore it went on with the test which lead to errors, among others ISPN-1965, might be caused by this.