ISPN-4389 Tests for suppressing state transfer with jmx fail

* Changed so cluster registry cache never has ST disabled
Updated readme file, failsafe plugin single test info
ISPN-4402 Add test for custom audit logger
ISPN-4409 Upgrade to LevelDB 0.7 and fix server test assertions

* Upgrade to LevelDB 0.7 in order to align with server's Guava
version which currently is 16.x.
* Fixed LevelDB server test assertions to avoid having to instantiate
the cache's marshaller client side.