Sortcolumn: Managing the Sequence of Arbitrary Ordered Elements (Shepherding Version)

To handle and persist the sequence of an arbitrarily ordered list, sorting information has to be managed and stored. The
Sortcolumn design pattern describes a way of managing the order of elements, without having to update all entries on every
change; only the actually reordered entries have to be updated. This is accomplished by using a numeric field to store the
ordering information and purposely leaving space between entries. Entries can then be reordered or inserted by using this
numeric space between two other entries. The Sortcolumn pattern describes how this numeric field values can be distributed, in
order to be able to insert, delete, and rearrange them easily.