ISPN-3117 (Non)TxAsyncBackupTest.testReplace fails randomly
ISPN-2281 Extend metadata support to internal cache entry structure

* This will enable for server endpoints that add extra metadata
(REST, Memcached) to pass in their entire metadata object to the
internal cache entry structure.
* Remove GetCacheEntryCommand and leave GetKeyValueCommand with
a flag to decide whether to return entry or value. This keeps
visitor small, making it easier for interceptor implementors.
* Remove VersionedPutKeyValueCommand and instead have
PutKeyValueCommand take metadata information which contains version.
* Removed all Versioned*Entry classes and replaced them with
classes that take metadata.
* Original cache entry classes (that take no metadata or version)
have been left in order to keep memory consumption to minimum
when neither version nor custom metadata are stored.
ISPN-2281 Convert REST server to store data passing in MIME information

* Created REST MimeMetadata class implementing Metadata to pass in
content type information.
* Added putAsync(K, V, Metadata).
* Remove lifespanTimeUnit and maxIdleTimeUnit from Metadata interface
which are not really used. Metadata implementers should provide
lifespan/maxIdle times in milliseconds.
* Fixed bug where Metadata*Entry instances were not correctly
determined when using a custom Metadata implementation. Added tests
for it too.
* Make all Metadata*Entry instances return the metadata in their cache
value, and not null.
* Remove unused key equivalence check in Hot Rod server.
ISPN-2281 Memcached server to pass flags and version via Metadata

* Added MemcachedMetadata to ship flags and version information.
* Added replace(K, V, Metadata) operation and added tests.
* Fixed bug where ReplaceCommand was not using valueEquivalence to
compare old and new value.
* Created ByteArrayCacheTest to exercise cache operations when
storing byte array key/value instances.
* Added externalizers for all metadata classes.
ISPN-2281 Add compatibility mode for REST and Memcached

* Added compatibility mode XML and programmatic configuration.
* Added REST and Memcached compatibility tests with Embedded
and Hot Rod.
* Add flags to signal operations original in server endpoints,
in particular Hot Rod and Memcached, which allows selecting
the correct type converter according to each server endpoint
requirements.
* Created type converter implementations for Hot Rod, Memcached
and Embedded modes. REST server does not really need it since
it alredy does a lot of type conversion based on content type.
* Enhance type converter interface to allow hooking operation
origins with their corresponding type converter instance, and
enable marshaller to be set in order to help interoperability
between endpoints.
* Fix metadata override bug
ISPN-2281 Redo EquivalentHashSet collection

* Fixed outdated DataContainer javadoc.
* Fixed headers, javadocs and make contructor of configuration
not public
ISPN-2281 Disable the MemcachedEncodingTest until the CLI encoding/codecs understand the new interoperable storage
remove any reference from configdocs till ISPN-3118 is implemented
enhanced the release script to also clear the release directory before every run
enhanced the release script to also make sure there is no locally modified  file
better logging of release progress