Unless it is specifically required, do not set the RateGOPSize to a
value other than -1.  This value (the default) causes RateGOPSize to
inherit the final value of GOPSize.  While setting config files to have
RateGOPSize = GOPSize does no immediate harm, it causes confusion when
GOPSize is altered (without altering RateGOPSize) and behaviour changes
relating to GPB.

 - Config files updated
 - Help text clarified

Resolves Ticket:37

From: David Flynn <davidf@rd.bbc.co.uk>