Split up files so that the scenario editor will build

- cCreature split into seperate file-pair from cMonster/cTownperson
- fileio.cpp split into general, party, and scenario sections
- classes.h file deleted

src/boe.graphutil.cpp

@@ -6,7 +6,7 @@
 
 #include "boe.global.h"
 
-#include "classes.h"
+#include "universe.h"
 #include "boe.graphutil.h"
 #include "boe.text.h"
 #include "boe.locutils.h"