Short circuit build_segment_list CC_BEHIND check
Support other endian serialization
Name serial unaligned_storage union
Short circuit ambient_mark_bfs test for child segments
Check length of g3 tmap inputs
Optimize render compare_children
Return int_fast32_t from find_connect_side
Overwrite oldest earthshaker even if not done

Otherwise the newest earthshaker will be lost.
Optimize set_ambient_sound_flags
Tighten processing of WALL_IS_DOORWAY flags
Use accessor for side::type
Use C++ inheritance for UI gadgets
Use unique_ptr for grs_subcanvas
Wrap pause window message in structure
Use C++ allocation for window-specific data
Move saving window pointer into helper
Add Valgrind poison stubs
Use special type for PHYSFSX_fgets
Remove trailing ^Z
Use std::string for UI_GADGET_BUTTON text