remove timelines prefix from js autocompleter and move empty elements translations

Conflicts:
	app/assets/javascripts/timelines_select_boxes.js
	config/locales/de.yml
	config/locales/en.yml
enable the controller pagination module to pass options to the search call to be more flexible
select2 autocompletion for projects' responsible
don't expect a project to have a responsible
adjust pagination on the model side to use the options and only pass the options if there are any
don't extend pagination model in user.rb, just use the stuff defined in principal.rb
make clear we don't actually need that param
refactor entering principal names in members tab
relocate anonymous user factory so the sequences defined for users do not interfere with that