- def.h: changed vectors for inorganics to contain uint8_t instead of bool which improves the performance when using std::fill and std::memset to batch-set the whole array
- survey.cpp: using std::memset instead of direct assignment to reset the inorganic vectors, also using the actual size of each vector for the call
- changelog.txt: add note concerning the changes
- defs.h: using mid_level_tile_incursion_base in region_tile_datum to store incursion data of world tile edges
- survey.cpp: commented out "not used" blocks of assignment in survey_mid_level_tile that no longer make sense now
- def.h: make attributes/fields of mid_level_tile_incursion_base available in mid_level_tile by inheriting from mid_level_tile_incursion_base which also allows treating mid_level_tile as a mid_level_tile_incursion_base