Fix a memory leaking problem.
Print some runtime error message.
Shutdown if the script file is not found in model txt.
Print the function name is a system script function return an error.
Fix a mistake in openbor_loadsample.
Use array index of list for script functions.
Use int instead of unsigned for scalex/y in gfxshadow.
musicoverlap is now supported for when using loading status screens.
xratio and zratio arguments added to background