MODE-1733 Added several concurrency tests that use persistent caches

None of the tests fail at this point.
MODE-1733 Eliminated in the tests only the excess Hibernate Search startup log messages

These messages were extremely prolific, since a new message was output once each time a
repository was started. This change only removes them from our build and test output.
MODE-1733 Changed SchematicEntryDelta behavior

The original problem is that the delta is being merged to a null entry
reference when the entry has been evicted from the cache. The correct
behavior would be to look up the persisted entry and merge the detal
with that. Infinispan is not behaving correctly.

This problem appears to be very similar to ISPN-2095, though we're
not using AtomicHashMap but have our own DeltaAware implementation
(called SchematicEntry).

The fix for ISPN-2095 involved changing AtomicHashMapProxy to use a
specific "DELTA_WRITE" cache flag that was added in Infinispan
5.1.6.FINAL. That means we don't have access to the fix in 5.1.2.FINAL,
so we need to provide an alternative solution for pre-5.1.6.FINAL releases.

The CacheContext now attempts to set that flag only when we're using
Infinispan 5.1.6 or later (e.g., if we can find the "DELTA_WRITE" flag),
but the changes still don't seem to correct the behavior with
Infinispan 5.1.2.FINAL, 5.1.6.FINAL or 5.1.8.Final. Even if it
worked on 5.1.6 or later, we would still have the issue when using
5.1.2.FINAL (which is all AS7.1.1 installations).

We need a solution that works with Infinispan 5.1.2 or later.
One option was to make the SchematicEntryLiteral instances no longer
implement DeltaAware. However, that means that we'd be changing the
class for the values we're storing in Infinispan. It also means that
we could not use DeltaAware in some environments (for example, when
we're using newer versions of Infinispan).

A better approach taken with this commit is to use different Delta
implementations depending upon the configuration. With this commit
there are two Delta implementations: one that works like before by
recording the Operations used to manipulate the documents, and a new
one that simply contains the whole document.

The benefit of this approach is that we can then choose which Delta
implementation we use based upon the Infinispan configuration and version:
- In local (non-clustered) caches, we actually don't need to compute a
  Delta. In this case we can use the whole document Delta and a
  different DocumentEditor that doesn't actually create any operations.
- In clustered caches that do not use eviction, we can use the
  diff-based Delta with an editor that does calculate the change
  operations. These Delta instances are correctly merged.
- In clustered caches that do use eviction, we need to use the
  whole-document Delta. And since this delta doesn't record operations,
  we could use a DocumentEditor that doesn't actually create operations.

All tests (including several new clustering tests) pass with these
changes. Additionally, the clustering test attached by the reporter
to MODE-1733 also passes with these changes, when using either
Infinispan 5.1.2.FINAL or 5.1.8.Final.
MODE-1733 Additional corrections and changes, per the code review