Cleanup split creator.c

creator.c was getting hard to follow.

- Split off argument and signal handling into own files.
- Move docstrings next to functions (to keep docs grouped with code).

source/creator/CMakeLists.txt

@@ -102,6 +102,10 @@ endif()
 # Setup the exe sources and buildinfo
 set(SRC
 	creator.c
+	creator_args.c
+	creator_signals.c
+
+	creator_intern.h
 )
 
 # MSVC 2010 gives linking errors with the manifest