Adding number of users for each language in get languages endpoint

[nunogoncalves]

Hi @vdaubry

I decided to make it an option because up until now the return was an array of strings instead of objects.

Since I have the app in production it would break things (V1 should have the return type always as a Language object (name: "", users:""... whatever). This way it wouldn't break things when adding fields like this example.

So in this case if we send the boolean, we get an array of objects, if not we still get an array of strings..
Not perfect, but what I came up with.

Let me know what you think.

[jayvdb]

Inconsistent use of single vs double quotes, but otherwise looks good.