Point Of Interest (Quest Details etc.)

@wsuchy , @jacekjursza and me - decided to implement QuestDetails API and NearbyQuests API (+ all related stuff) in single brunch (because these tasks are strongly coupled).

At the moment - this pull request must be only reviewed and not merged!
I have thought, that there might be returned large documents from Solr - so, I decided to avoid copying, and pass them by reference.