- Move detection code used by createInstance & MetaEngine to a common header - detection_internal.h
- Move steam-related method & table to detection_steam.h
- More info in comments.
- Also, we remove the static keyword so other TU's can use the functions defined.
- This change has a catch.
- Because creating an instance depends on game detection code from detection.cpp, we cannot exclude it from Scumm.
- For Statically linked Scumm, we can simply exclude these detection files, because they're already being built.
- For dynamically linked Scumm, we can add it to our executable.
- Thus, for dynamically linked Scumm, one catch is that we have duplicated code (detection.o in our executable, as well as scumm.dll), but that shouldn't be a big problem considering the advantage it gives us: Detection without a plugin loading.
