ISPN-3241 Don't make the memcached server overwrite the cache
configuraiton if it already exists
ISPN-3239 LevelDB Cache Store to support JNI with proper fallback to
pure Java implementation
ISPN-3217 Rebalance doesn't store data into cache store

In non-tx mode, if the originator of a put command is an owner, it will
only write the entry when the command is forwarded back to it by the
primary owner. But this rule shouldn't apply to state transfer puts,
which use the CACHE_MODE_LOCAL and SKIP_OWNERSHIP_CHECK flags.

DistCacheStoreInterceptor is now used for replicated caches as well.
ISPN-3197 Message ordering of Get and Invalidation can cause L1 to be inconsistent.

* Implemented single entry point for concurrent gets.
* Also support concurrent invalidation for reads with limited blocking
* Added tests for various concurrency/edge issues