nsq binary interface

[cantsin]

the current nsq interface leaves something to be desired. currently library/http.lua, library/nsq.lua, library/nsqc.lua offer overlapping ways to do the same thing. We really want one good binary interface.

Options:

• improve nsqc
• build our own (i suggest https://github.com/ToxicFrog/vstruct as that is a pure lua module)