Update beck-online.js

1. beck-online.js
Added support for beck-online "Leitsatzkartei" LSK (database of leading records), i.e. scraping of articles where beck-online does not have the article itself but only information about the article

2. juris
Added new translator for the German legal database Juris.
This is fine too, but if you want (and if this works across the board), you can use a single regexp match for all three parts.
```
var m = src.trim().match(/([^,]+?)(\b\d{4})?,\s*(\d+)$/);
if (m) {
  item.journalTitle = ZU.trimInternal(m[1]);
  if (m[2]) item.date = m[2];
  item.pages = m[3];
}
```