Added GetDefaultSaveDir(suffix) which fetches the default "Application

Data" path for the current user from the registry, appends the suffix,
creates the subdirectory if it doesn't exist, then returns a string from
the heap.
This path is the new default "savedir" location on Windows. Tested on
98/2K/XP.
Changed code that sets the pwd to the directory containing the executable.
Originally for BEOS only, now working and enabled for Windows also.

src/win32_print.h

@@ -19,4 +19,7 @@ extern const char *SurfacePrint( SDL_Surface *surf,
 			         int showdialog );
 extern int IsPrinterAvailable( void );
 
+/* additional windows functions requiring <windows.h> */
+extern char *GetDefaultSaveDir(const char *suffix);
+
 #endif