Refactor ensure and ensure-not parsers
Refactor ensure and ensure-not parsers

ceninan/factor,bpollack/factor,mcandre/factor,Keyholder/factor,mcandre/factor,AlexIljin/factor,ehird/factor,ceninan/factor,kingcons/factor,tgunr/factor,littledan/Factor,bpollack/factor,slavapestov/factor,mecon/factor,erg/factor,factor/factor,slavapestov/factor,littledan/Factor,mcandre/factor,AlexIljin/factor,nicolas-p/factor,mecon/factor,Keyholder/factor,nicolas-p/factor,factor/factor,mecon/factor,mrjbq7/factor,seckar/factor,nicolas-p/factor,erg/factor,AlexIljin/factor,dch/factor,Keyholder/factor,nicolas-p/factor,dharmatech/factor,bpollack/factor,slavapestov/factor,sarvex/factor-lang,factor/factor,slavapestov/factor,sarvex/factor-lang,kingcons/factor,slavapestov/factor,bpollack/factor,ceninan/factor,tgunr/factor,bjourne/factor,sarvex/factor-lang,bjourne/factor,nicolas-p/factor,mcandre/factor,sarvex/factor-lang,erg/factor,cataska/factor,sarvex/factor-lang,ceninan/factor,mcandre/factor,AlexIljin/factor,factor/factor,nicolas-p/factor,dharmatech/factor,erg/factor,cataska/factor,ehird/factor,mrjbq7/factor,bpollack/factor,kingcons/factor,bpollack/factor,littledan/Factor,tgunr/factor,dharmatech/factor,erg/factor,tgunr/factor,erg/factor,mcandre/factor,AlexIljin/factor,jwmerrill/factor,dch/factor,bjourne/factor,ehird/factor,dch/factor,mecon/factor,mcandre/factor,bjourne/factor,littledan/Factor,jwmerrill/factor,jwmerrill/factor,sarvex/factor-lang,bjourne/factor,seckar/factor,erg/factor,mrjbq7/factor,bjourne/factor,dch/factor,seckar/factor,mrjbq7/factor,mrjbq7/factor,bjourne/factor,slavapestov/factor,slavapestov/factor,tgunr/factor,nicolas-p/factor,cataska/factor,cataska/factor,mrjbq7/factor,AlexIljin/factor,tgunr/factor,mecon/factor,bpollack/factor,dch/factor,kingcons/factor,dch/factor,mecon/factor,mecon/factor,factor/factor,AlexIljin/factor,sarvex/factor-lang,factor/factor