Add drag and drop and other dynamic behavior to the admin panels containing enum lists

[Ryan J Ollos <ryan.j.ollos@…>]

A reworked version of ​th:AdminEnumListPlugin will be provided as a patch to Trac. The behavior will apply to the Priorities, Resolutions, Ticket Types and Severities panels.

The following behaviors will be provided in the initial version of the patch:

• The list can be sorted by drag and drop of the items.
• The column of select elements is hidden.
• A Revert changes button is added. The button is disabled until a change is made.
• The Save changes button is disabled until a change is made.
• The Remove selected items button is disabled until a checkbox is selected.
• Addition of a Select All checkbox in the table header.

Similar behavior will be applied to other admin pages for consistency, where applicable.