[fix #4928] Made journal notes shown in search.

- Added tests and specs for bug #4928
- Examined bug
  - Added debug output to examine event contents
  - Examined journals
- Added highlight_first helper
  - Used last_journal instead of #journals.last
  - Fixed Journalized#last_journal to work when eager loading messed up search
  - Fixed how journals are sorted when they are loaded (by version instead
    of created_at)
- Added notes anchor when required
  - Added notes anchor when required
  - Note anchor uses version of journal note itself, not version of work package
- Fixed failed test in
  functional/wiki_controlller_test.rb:WikiControllerTest
  #test_update_stale_page_should_not_raise_an_error
- Fixed spec failures.
- Converted search helper test -> spec, removed test file.
- Moved helper methods from string to controller
- Fixed search controller spec.
- Temporary added isolated suite run to travis for
  work_package_activity_provider_spec
- Removed temporary job for travis.
Merge pull request #1053 from waterlink/bugfix/4928_search_journal_note_hits_not_shown