Cache API review

[Dmitriy Setrakyan <ds...@apache.org>]

Hello Igniters,

I have reviewed the cache public API and still found a few inconsistencies:

- GridCache, CacheProjection, GridCachePeekMode are still in public API.
They all should be gone in my view.
- GridCacheVersionedEntry should be moved either to internal API or back to
GridGain (I prefer the latter).
- CacheEntry class is not needed in my view anymore. I believe the
CacheEntry from JCache spec is sufficient.
- CacheEntryEvent should be moved to internal package.
- CacheConfiguration should be cleaned up as it still has methods
pertaining to GridGain.

Please reply if you left these classes/methods on purpose. If not, I will
file a ticket to remove them.

D.