i18n support

[Nriver]

translated some dialogs

[eliandoran]

@Nriver , I've found a really nice extension for VS Code, if you're a user of this editor.
It's called i18n-ally and I set up a basic integration with it.

It should allow you to see the keys that are in use, the progress in each language and the translation tree:

In addition it also has this beautiful inline preview of the translations:

If you're interested do would need to grab the latest changes from my PR and install the extension for VS Code.

[eliandoran]

@Nriver , the PR got accidentally closed when merging #248 .
Please open a new one targeting the develop branch. I'll also give you dev rights on the repo, so you can open a PR directly on the repo without the need of a fork (if you do this be careful not to accidentally create the PR on zadam's repo).

[Nriver]

I find i18n-ally quite nice, but being a fan of JetBrains, I prefer using WebStorm : D

I'll make another PR then.

[meichthys]

Moving this to an issue (#338) since work is being done on this.