Generate other build recipes from mmakefile.src

[iamleeg]

There are many ways to build Amiga-Smalltalk:

• using an Amiga compiler, and the NDK, on an Amiga.
• using an AROS or MorphOS compiler, and their NDKs, in AROS or Morphos: this is a special case and I don't know if anyone is doing either (or trying MorphOS at all).
• using an Amiga cross-compiler, somewhere else.
• using an AROS cross-compiler, on a Unix-like system, in AROS meta make.
• using a Linux compiler, on Linux, and linking the axruntime.
• theoretically others that are definitely out of scope.

It'd be helpful if we only had one place to say which files are used in which targets. It seems reasonable to make that one place mmakefile.src, because it already is a configuration for generating another makefile, so we could use it to generate all other makefiles.

This points to making a configure script (actually two, one for Amiga-like OS and one for Unix-like OS) that takes the target definitions in mmakefile.src and makes build recipes.