This macro returns whether or not the passed file number is a
	big save (BIGSAV) file number.  Big saves are global saves made
	either at operator request or by the Sequencer.

	file_number	save/restore file number to test

	This macro returns values as follows:

	TRUE			this is a BIGSAV file number
	FALSE			this is not a BIGSAV file number

	This macro is found in: macro_h

	Related macros: