Reduce number of compile-time warnings

Hi,

I decided to try to fix issue #1658 . Here's my first attempt. 

- fixed most of the `Wrong number of args` warnings
- fixed couple of `Use of undeclared Var` in object.cljs, app.cljs and command.cljs
Don't remember what it was before, but it used to track more information about position. It actually gets called with 3 params here: https://github.com/brabadu/LightTable/blob/master/src/lt/objs/langs/behaviors.cljs#L116

That code could use a good bit of refactoring, but it'll actually get a lot simpler if we move to the newly proposed structure for behaviors.