ISPN-4363 Add documentation for Cluster Listeners

* Added documentation about cluster listeners
* Added documentation about filters
* Added documentation about retry
ISPN-4323 ConditionalOperationsConcurrentWriteSkewTest fails randomly

* Changed 500 invocation tests to stress as they can last for minutes
* Moved more simple test to separate file and still functional
ISPN-4651 LevelDB crashes JVM when stop() is called concurrently with write()
ISPN-3979 JdbcStringBasedStore loading of Key2StringMapper class is too
restrictive

* Key2StringMapper class is now loaded using ClassLoader from
* GlobalConfiguration
ISPN-4649 RemoveCommand does not activate the key in Passivation

* No tests added since ISPN-4559 tests cover this scenario
ISPN-4559 Replace fails with cache loader

* Tests all the conditional commands
ISPN-4657 Allow for customization of SearchWorkCreator used by the QueryInterceptor
ISPN-4654 AND over range queries does not work (indexless query)

* Some subscription gets mistakenly suspended.

* also fix equals() and hashCode() of RegexCondition