various browser improvements

* improvements to e2e testing
* change order of constraints in JSON in order to accomodate ML search API validation issue
* display (accurate) vote counts for contributor dialog and logged-in dropdown
* display "you must log in to answer" if not logged in
* icon for StackOverflow question link
* remove mocks from running app
* tweak REAMDE
* change labels to `votes` from `score`
* fix paging
* fix sorting
* show spinner while searching
* enable stacktrace on dbTeardown in cleanstart to assist troubleshooting

Please see individual commits for more detail.