Use fork and join technique for querying the indexing tree

Migrated from NovaTec Jira. Originalticket: INSPECTIT-585

Since the storage is written for Java 7, as soon as we switch to it on the CMR, I would propose that fork and join technique of Java 7 should be used when we query the indexing tree. The advantage should be that the separate branches that need to be queried in the same query, can be processed in parallel. This would in general brings us the faster query.

However, there should be a selection of situations where technique should be used. It should not be used always, since overhead for using it can be bigger than what we would get with parallelism:

More about Fork & Join in JDK 7: http://download.oracle.com/javase/tutorial/essential/concurrency/forkjoin.html

Pseudo-Code