Even that part's the same in these three games… except for the 27 small
places where it isn't, 7 of which are purely coding style cosmetics.
Completes P0224, funded by Splashman and -Tom-.
The .PTN functions, vector functions, and egc_copy_rect_1_to_0_1()
(finally!) from TH01, as well as playfld.hpp from all games(finally!),
together with a bunch of other functions in their vicinity.
Part of P0201, funded by Ember2528 and Yanga.
eeb4e7e changed the final C translation unit that used this header to
C++, and we got some more helpful inline functions upcoming.
Part of P0136, funded by [Anonymous].
nmlgc