[Bug 886945] Translation fixes

See [Bug 886945](https://bugzilla.mozilla.org/show_bug.cgi?id=886945) for reference.

There were a few items in there that looked like they should work fine or might be missing a translation in general:
- Text of invite email is in English; email text is wrapped in a {% trans %} tag and should work ok. Might be missing a translation.
- Editing profile, values of "Visible to:" are in English (Mozillians/Public); I remember from my notes that we were not wanting translation around these. Please verify.
- The template syntax shows that the text in `phonebook/invited.html` should be translated: https://github.com/juliaelman/mozillians/blob/26e65b9615b7cc7d8d5aa59015416aeaec3c8258/apps/phonebook/templates/phonebook/invited.html#L10