Fix failing feature specs

Squashed commit of the following:
- fix some feature specs
- rewrite outdated rspec matchers
- fix typo
- fix specs' rewrite mistakes
- fix 'be' matchers
- update test file references
- fix filter_panel spec
- fix filter_set specs
- fix vocabulary module spec
- fix media_entries spec
- fix typos
- fix media_resources_index spec
- fix media_set_actions specs
- fix meta_data specs
- fix permissions_controller specs
- fix randomly failing modal related specs
- fix uberadmin specs
- fix meta_data_institutional_groups failing spec
- fix meta_data specs
- fix media_set_actions specs
- try to get rid of login failures
- another fix for filter_set spec
- another try to get rid of login failures
- use firefox in media_set_actions spec
- use more reliable matcher