sets: make ?adjoin a generic method.
sets: make ?adjoin a generic method.

bpollack/factor,AlexIljin/factor,slavapestov/factor,slavapestov/factor,bjourne/factor,mrjbq7/factor,dch/factor,nicolas-p/factor,sarvex/factor-lang,bpollack/factor,nicolas-p/factor,dch/factor,bjourne/factor,bjourne/factor,AlexIljin/factor,mrjbq7/factor,sarvex/factor-lang,factor/factor,tgunr/factor,bpollack/factor,AlexIljin/factor,sarvex/factor-lang,tgunr/factor,nicolas-p/factor,bjourne/factor,nicolas-p/factor,sarvex/factor-lang,tgunr/factor,sarvex/factor-lang,dch/factor,bpollack/factor,mrjbq7/factor,bjourne/factor,AlexIljin/factor,nicolas-p/factor,mrjbq7/factor,nicolas-p/factor,bpollack/factor,AlexIljin/factor,dch/factor,bpollack/factor,AlexIljin/factor,tgunr/factor,mrjbq7/factor,slavapestov/factor,factor/factor,mrjbq7/factor,dch/factor,factor/factor,bpollack/factor,slavapestov/factor,factor/factor,nicolas-p/factor,tgunr/factor,slavapestov/factor,factor/factor,dch/factor,AlexIljin/factor,factor/factor,slavapestov/factor,tgunr/factor,sarvex/factor-lang,bjourne/factor,sarvex/factor-lang,bjourne/factor,slavapestov/factor