1. Simplification - OperationSelector introduced
2. Removed cacheManagerdestroy probability as it was doing exactly the same operations as the destroyCacheProb

No changes in the test logic.
Creating a new CachingManager will close the existing one to avoid resource leak.

It's reusing the same CachingProvider. There is the CLOSE_CACHING_PROVIDER operation, but according to JCache specification a provider is still functional even after calling provider.close() so it's safe.
Merge pull request #452 from jerrinot/fix/icache-mangle-test

ICache Mangle Test Fixes