await proxy store aliased action's result

[wswoodruff]

I looked around in the docs and issues and might have missed it, but couldn't find a solution to provide me with an aliased action's result in a proxy store.

As I learn how to work in this distributed area, to avoid headache and to ensure I know where state is, I've forced all proxy store actions to be aliased.

Normally my actions return an array for [err, result] — I deal with that in the dispatchResponder for my background store — but I'd like to await for [err, result] in my containers.

The intention is for giving user feedback when they, ex: click a login button. We want to tell the user if there was an error, or we want to clear the form and route to another page or show a success message or whatever.

[jlalmes]

I made this PR - does the solve the issue you are describing?
#262