implemented new filter_form in records index
  - users can add one empty annotation_filter_term
  - users can remove all existing annotation_filter_terms

removed auto submit of the new filter form from assets/javascript/records.js.coffee

added logic to records_controller to make adding/removing annotation_filter_terms work,
and to present user with project_affiliation_filter_term even if there is not
one already present

update record_filter.rb, annotation_filter_term.rb and project_affiliation_filter_term.rb
to better respond to empty parameters in submitted forms

ALL TESTS PASS