Added map layer construction for non-existent layers after map concatenation.
Added and adapted code from impact-infinite. Added chaining maps to east direction.
Added chaining maps to south direction.
Fixed bug with map chaining not loading maps diagonal to initial map.
Added map chaining to north direction. Added existing entities repositioning on current map.
Added map chaining to south direction. Added existing entities repositioning on current map.
Added large super map for testing. Fixed JSHint errors.