Implement type checking

[Raynos]

there are three ways we can implement type checking:

• integrate jsig with typescript. Typescript already supports jsdoc so we can hook into that.
• integrate jsig with flow. Flow also supports jsdoc so we can hook into that. Alternatively flow supports comments so we can write a "transpiler" that generates flow code.
• write our own type checker. I started more then a year ago. I've recently restarted from scratch with https://github.com/Raynos/jsig2 . Writing our own checker takes longer but gives us more control.

Ive tried to use flow. I've experimented with it for a few days but soon learned the type system was too optional for my liking. I believe having an "any" type is bad and want to correct it with my own type checker

If my type checker ever hits v0.1 I'll merge it into this org. Right now I'm just hacking on master

[Raynos]

After a few weeks of work I've gotten the type checker into a 0.1.x state. ( https://github.com/Raynos/jsig2 ).

If there is any interest in having a type checker build for jsig I can merge it into this org.

cc @jden

[junosuarez]

@Raynos awesome work, very cool stuff. Feel free to make executive decisions re merging to this org or using the work in conjunction with other projects. :+1: