Int32 types

[rambleraptor]

From #17

I think it's probably better to leave it this way, but as a note there is no int32 type really, and the maximum size 2^53-1 so int64 isn't possible: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER.

I think we should probably support it anyway, and maybe implement an int64 as a string in javascript for safety's sake. @hudlow might have thoughts on this.