First pass at showing errors via i18n

[tmeasday]

Can I get your thoughts on this @stubailo?

A couple of things:

1. Where to put the helper and is it weird to get the translation in the helper? (it means I have to do vaguely funky things to get a "symbol" from another package)
2. Are we going to i18n-ise the whole app? Because that's probably going to be a chunk of work. I wonder if we can just show this pattern somehow
3. It's kind of annoying to use but that's probably just how it goes with this stuff. All-packages doesn't make it easy...

[stubailo]

This looks great to me - I love the namespacing. Although, this is one place there could be a lot of benefit to having all of the translations in one file - that way you could just give the file to a translation service and get all of the different languages, right?

[tmeasday]

Well I think we are running up against a limitation of the all-package approach here perhaps?

[stubailo]

Should we wait on this until the modules preview drops?

[tmeasday]

We are going to do this properly when we hit 1.3 / modules #59