unix.ffi: Add the man 2 signal() function call.
unix.ffi: Add the man 2 signal() function call.

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