Fixes

• [avplug] version bump required for ffmpeg-7.1.1/8.0 changes #318
• [ode] Error: you can only #define dSINGLE or dDOUBLE, not both #309

New

• [repo] move win32 .rc and .ico to contrib
• [repo] move progtype.h to include/fteqw/math/scalar.h
• [repo] move mathlib.h to include/fteqw/math/vector.h
• [build] require -std>=C11
• [math] #define align[as/of] as _Align[as/of] for -std<C23 and -std<C++11
• [math] update vector/matrix types
• [math] use #define do while instead of [inline] function for cross/vector product
• [math] use #define FTE_VECTOR(N,T,A,prefix,name,suffix) to define vector types
• [math] introduce enum align as alignment modes