This removes SystemString, SystemChar, etc.
All filepaths and log strings are assumed to be UTF-8,
with conversions to UTF-16 for Windows APIs as appropriate.
Updates amuse, athena, boo, kabufua and nod
Avoids indirect inclusions where applicable and includes the necessary
headers as used by the interface. This way, it prevents code from
failing to compile due to changes in other header inclusions.