#74  added find_jobs function in model and controller. added new model test. put search, filter and sort in one menu in index
#74 english and german version for labels in index.html and adapted css
#72 added dropdown for chairs, added placeholders for start and end date
had to adapt test after last commits
improved code to coding coventions
Merge remote-tracking branch 'origin/develop-ja-sort-search-filter' into develop-ja-jobs-history

Conflicts:
	app/views/job_offers/index.html.erb
	config/locales/views/job_offers/en.yml
	config/routes.rb
	spec/models/job_offer_spec.rb
Merged commit da07f54
added migration from commit 21fdebd
Merged refinements for chairs page from develop-ak into develop branch
Merge remote-tracking branch 'origin/develop' into develop-js