Replace `MutablePropertyState` with a getter and setter closure.
Replace `MutablePropertyState` with a getter and setter closure.

victorlin/ReactiveCocoa,ikesyo/ReactiveCocoa,tzongw/ReactiveCocoa,ikesyo/ReactiveCocoa,tzongw/ReactiveCocoa,victorlin/ReactiveCocoa,ReactiveCocoa/ReactiveSwift,smilypeda/ReactiveCocoa,andersio/ReactiveCocoa,calebd/ReactiveCocoa,ReactiveCocoa/ReactiveSwift,rpowelll/ReactiveCocoa,sandyway/ReactiveCocoa,walkingsmarts/ReactiveCocoa,rpowelll/ReactiveCocoa,walkingsmarts/ReactiveCocoa,walkingsmarts/ReactiveCocoa,andersio/ReactiveCocoa,victorlin/ReactiveCocoa,ReactiveCocoa/ReactiveSwift,calebd/ReactiveCocoa,RuiAAPeres/ReactiveCocoa,RuiAAPeres/ReactiveCocoa,RuiAAPeres/ReactiveCocoa,smilypeda/ReactiveCocoa,rpowelll/ReactiveCocoa,ohwutup/ReactiveCocoa,sandyway/ReactiveCocoa,tzongw/ReactiveCocoa,calebd/ReactiveCocoa,ohwutup/ReactiveCocoa,sandyway/ReactiveCocoa,ohwutup/ReactiveCocoa,andersio/ReactiveCocoa,smilypeda/ReactiveCocoa