WorldGenerator: global map corridor system.

[realGuybrush]

On the global map there should be corridors, in which player moves. Coridors are interconnected by doors and passages. When player enters one corridor, it is uploaded by WorldGenerator, with all stuff, which was inside. Previous corridor is removed from scene. Entities, which chased player, can enter doors after him/her. Internal structure of each corridor is based on biomes, which affect tiles connected by corridor.

[realGuybrush]

Will remain until interCorridorMovement for entities is added.