A little bit of tidying of `OPGroupOperation` as well as resolving an error that causes `OPGroupOperation` to not function because it was calling `[super init]` and not `[self init]` within `initWithOperations:`
A little bit of tidying of `OPGroupOperation` as well as resolving an error that causes `OPGroupOperation` to not function because it was calling `[super init]` and not `[self init]` within `initWithOperations:`

colinmcardell/Operative,pronebird/Operative,Kabal/Operative