NSTimeIntervalSince1970

[Lyndon Tremblay]

Apple NSDate documentation states that a constant named 
'NSTimeIntervalSince1970' is declared as an NSTimeInterval, with the 
description "Seconds from 1 January 1970 to reference date, 1 January 2001"

GNUstep NSDate header does not have this. I might not quite understand the 
description for the constant's use, but base/NSDate.h has declared 
"GSTimeNow()". Would these be the same? If so, I'm not sure how Apple's 
Foundation would update this constant.

--Lyndon