Moves a few settings to a "Display" panel.
CustomFieldsController#list moved to #index.
CustomFieldsController refactoring.
Make use of tracker_ids association in issue custom field form.
Project jump box fix.
Do not show Category field when categories are not defined.
Slight visual changes on the issue form.
Adds custom fields functional tests.
Use a textarea for custom fields possible values (#2472).
Makes subject field get focus on 'New issue' form (#2522).
