Update the Amiga Intuition window port (AMII/AMIV) for the 3.7
window_procs API. Key changes:
- Update all window function signatures for 3.7
- Add assembly trampolines for AmigaOS register-based callbacks
- Convert all K&R function definitions to C99
- Add cross-compilation build system (cross-pre1/pre2/post.370)
using bebbo's m68k-amigaos-gcc with -noixemul -std=gnu17 -m68000
- Clipping fixes: viewport centering, simplified ScrollRaster,
duplicate Ctrl-R suppression, glyph buffer invalidation
- Add menucolor support in menu rendering
- Move native txt2iff.c and xpm2iff.c to outdated/
- Add nethack.cnf and README.amiga
Move the active Amiga source files back into their proper locations.
Legacy native build files (Makefile.ami, Build.ami, etc.) remain
in outdated/ as they are not used by the cross-compilation build.
