adds a super cool ranking algorithm and  a reCaptcha
fixes recaptcha error message
Merge branch 'develop' of https://github.com/dirkschumacher/iUPB into develop

# By Dirk Schumacher
# Via Dirk Schumacher
* 'develop' of https://github.com/dirkschumacher/iUPB:
  adds a label to locale
  adds limits to ad model fields and some translations
  makes category list look nicer + changes order of categories to asc + orders posts by date desc