FIX: non-latin headers

[asakasinsky]

Problem:
if the "text" value passed to "slugify" function consist only non-latin characters (cyrillic, for example), regular expression match === null. And we get an error on "join('-')".
Solution:
I assigned to match result (if match===null) a timestamp. This solution a little bad for the semantics, but completely solve the problem

[Akurganow]

I have the same problem

[kerim]

I'm having this problem now. I see that a solution has been offered, but I'm not sure how to implement this solution locally (since it doesn't seem to have been updated in the code yet)?

[andrewkharook]

This solution fixes the page display but menu in sidebar still does not work correctly.

[rstacruz]

Thanks, I think the better solution is to use .toLowerCase().replace(/[_ \(\)\[\]]/g, '-') or similar.