* Use an Infinispan cache to maintain pending puts, which avoids
the need to control it's memory consumption in the critical path
of putFromLoad.
* This cache is shared by all regions, and it's configured with
aggressive expiration settings to avoid piling up pending put
operations.
* Added a 2LC stress test that tests behaivour and performance
of 2LC under multiple situations, such as entity inserts, updates,
find via PK, find via query and deletes.
* Some other minor performance enhancements, such as avoiding
classloader aware cache wrapper if using 2LC locally.
* Remove cache adapter to reduce construction of useless objects.
* Cache flagged caches in order to avoid recomputing decorated
caches all the time, which reduces memory consumption.
* Skip locking for timestamp updates and separate timestamp region
implementations for local vs clustered scenarios.
Galder Zamarreño
Strong Liu
Steve Ebersole
Sanne Grinovero
JPAV
Emmanuel Bernard
Gail Badner