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'm wondering... what would you say about using strrpos here, because it's more analogous to what is done in startsWith? Of course, right hand side will be non-zero then :(