filename	IN:	Name of the file
	palette	IN:	Buffer containing the palette to be written
	overwrite	IN:	Flag identifying the palette to be written
	filemode	IN:	File access mode

	Purpose	Writes a palette to the file.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	This routine provides more control of palette write operations than DFPaddpal. Note that the combination filemode="w" and overwrite=1 has no meaning and will result in an error condition. To overwrite a palette, filename must be the same filename as the last file accessed through the DFP interface.
		Valid values for overwrite are: 1 to overwrite last palette; 0 to write a new palette.
		Valid values for filemode are: "a" to append the palette to the file and "w" to create a new file.
		The palette buffer must be at least 768 bytes in length.

	FORTRAN	integer function dpppal(filename, palette, overwrite, filemode)
		character*(*) filename, palette, filemode
		integer overwrite