A new method for translators to work

[pento]

Rather than just going through a list of strings to translate, allow the user to translate one random string at a time, based on any restrictions they want:

- Pick from one, some, or all projects.
- Restrict to one, some or all languages.
- Perhaps have an option for reviewing already translated strings in the random mix? Depends on if it gets popular enough to run low on un-translated strings.

The algorithm for picking random strings could perhaps use some weighting, too:

- Give weight to less popular projects, more popular projects are likely to get translators who will just translate all strings.