msgpack: support streaming writes of arrays and maps.
msgpack: support streaming writes of arrays and maps.

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