Keyword not found recommendations

For issue #888.
Why is this done? Doesn't `difflib` handle Unicode data with non-ASCII characters just fine? If the idea is to map characters like `ä` to `a`, I don't see why it should be done. If I have a keyword `Hyvä`, I don't see why `Hyva` should be somehow closer to it than e.g. `Hyve`.

As I already mentioned above, importing `unicodedata` is extremely slow on Jython. It should thus be only used if absolutely necessary and even then probably not when running Jython.