functors: add MIXIN:, SINGLETON:
functors: add MIXIN:, SINGLETON:

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