Add an optionalize operator
Add an optionalize operator

calebd/ReactiveCocoa,ohwutup/ReactiveCocoa,ohwutup/ReactiveCocoa,walkingsmarts/ReactiveCocoa,ikesyo/Rex,RACCommunity/Rex,RACCommunity/Rex,neilpa/Rex,walkingsmarts/ReactiveCocoa,bjarkehs/Rex,ohwutup/ReactiveCocoa,nanoxd/Rex,ikesyo/Rex,neilpa/Rex,bjarkehs/Rex,nanoxd/Rex,calebd/ReactiveCocoa,calebd/ReactiveCocoa,RACCommunity/Rex,skyylex/Rex,avalanched/Rex,walkingsmarts/ReactiveCocoa