added new fragment user_list for show chair/job_offer
added fragment to chair
added user list to job_offer show, added some translations
added some error catching for worker lists
Merge branch 'develop-ja' into develop-ja-worker-list
Conflicts solved, adopted layout of worker lists to fit in
#146 #148
forgot to uncomment lines after testing
Merge branch 'develop-ja' of https://github.com/tkowark/hpi-hiwi-portal into develop-ja