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 seems to be really to only place where date, journal name (abbreviated) and starting page are written. I am thinking if it is the best possible method to extract the different parts by an regexp for the date. It would also be possible to use split on `,`. Opinions?