Cocoa compatability header file

[Fred Kiefer]

I would like to add a new header file to the GNUstep GUI module, which 
would be placed in a subdirectory Cocoa and would help with porting 
stuff from Apple to GNUstep. In this file we could put all the 
extensions we don't want to see in the GNUstep headers. My current 
working copy of this file is attached.
I don't see any problem for the rest of GNUstep here, but as some 
GNustepers are rather Cocoa sceptic I would like to give these a chance 
to oppose this addition.

Cheers
Fred

#include <Foundation/Foundation.h>
#include <AppKit/AppKit.h>

#ifndef M_PI
#define M_PI 3.1415926535897932384626433
#endif

typedef BOOL bool;
#define false NO
#define true YES