ISPN-4384 CacheNotifierImplInitialTransferDistTest test instability

* Dist initial transfer could fail erroneously if remote/local batch
* completed at about the same time
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.