Stack PR 2 on PR 1 so one restart covers both. The shared Library
tag_mode now takes all, any and untagged on the route, the filter, saved
views and Refine's Tag match; untagged still refuses tags and a folder
combines with every mode.
Refs #444
Refine this view on the Prompt library gains the concept's Folder (folders
below an output root, read when the dialog opens) and a Tag match select
(All / Any). The listing takes folder and tag_mode, matches folders on the
normalized file_path under every spelling of each output root, echoes both
so a stale server is an error, and saved Library views keep them. Recorded
as D150.
Refs #444
Vito Sansevero