Subtracts an msf to the receiver.
Original signature is '- (DRMSF*) msfBySubtracting:(DRMSF*)msf'


- msf (DRMSF)
- The msf to subtract from the receiver

A new DRMSF object totalling the difference of the reciever and msf

- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)