Ability to customize order of Resources

Original requirement:

http://bugs.sakaiproject.org/jira/browse/REQ-378

"Instructors should be able to set documents/files within and outside of folders, as well as folders in resources in whatever order they choose, rather than having documents appear in alphabetical order. An instructor may have several folders, and files outside of folders, in the Resources area – Homework, Assignments, Images, Maps, Research Resources List. Currently, Sakai puts these items in alphabetical order.

This occasionally forces faculty to rename their resources in manipulative ways simply to have the arrangement of folders and files happen in the way they wish.

The site owner should be able to determine the order in which folders and files appear. The site owner should also be able to determine the order in which documents/files within a folder appear. "

Use cases:

1. An instructor sets a "default" ordering for a site's resources, which need not adhere to any sorting algorithm.
2. A student wants to re-sort items alphabetically, and then later return their view to the default sorting the instructor established.

Requirements:

1. The UI (maintainer role only) for the ordering interface should be separated out to a different view as not to clutter the resource list interface.
2. The UI (maintainer role only) for changing the sort should follow existing standards in the Sakai interface (sorting arrows to change position).
3. The UI (maintainer role only) for changing the sort should allow an alternate sorting method (perhaps combined with the other controls) that lets maintainers specify a numerical sort order in text inputs. This is similar to functionality from other CMSs, as well as the Netflix Queue.
4. A site user can still re-sort the items according to their preferences, but always have a quick way to restore the "default" ordering that the instructor has established.