Populate a list with devices, volumes and assigns from the DOS list at
construction. This class has no additional public attributes or methods.
Entries are appended in three passes: devices, volumes, then assigns, in
their DOS-list traversal order. No sorting, periodic refresh or
disk-change handler is installed.
The default format has five columns: icon, name, percentage used, free
space and used space, with numeric columns right-aligned. A non-NULL
caller List_Format suppresses this default. Construction installs its
own construction, destruction and display hooks after superclass
creation. Preserve those hooks for the class's private entry records;
entries are not ordinary strings.