reconstruct full table of bit allocations per mode

support making all definitions static so you can have multiple copies of file (with different #ifdefs);
move all tables to end of file (this will have to be undone later because IIRC it's not compatible with C++ or with some compilers or something, but it'll make my life easier in the interim);

support texture rotation; better interaction of mouse centering & VC6 debugger; fix in-place conversion when mca blocks are written in different order

fix incorrectly-named assert, attempt to fix (char) cast warning (tricky since char's signedness is unknown)