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
Yes, there's number of places that import sidebar/comand.cljs and use exec! function from this file, rather then requiring objs/command. 

I was going to fix it in separate PR