ISPN-4582 JpaStoreTest random failures

* Set threadCount to 1 in surefire plugin
ISPN-4470 Remove tabs and fix other formatting issues
ISPN-4470 RemoteCache's size() method should compute size globally

* A new statistic added that shows the number of keys a cache is
primary owner for. Use that statistic, calculated cluster wide,
to count the total number of entries in the cluster for the
remote cache.
* If statistics disabled, or using Hot Rod 1.x protocol,
keySet().size() is used as fallback.