Whitespace.
Allow access to the additional columns that were found.
Whitespace.
Rename "ignore_extra_columns" to "allow_extra_columns".

We're not just ignoring them any more!
spelling: preceed* => preced*
Create add_ methods for links to profile items and subject mappings.
Add support for setting tags when creating subject mappings.
Consolidate get() attempts to single statement.
Revise file_path doc text for correctness.
D:D:A:Purger extract _add_timeline_event
D:D:A:Purger extract _destination_dir method
whitespace
D:D:A:Purger extract _purge_unarchived
D:D:A:Purger purge archived allocations
D:D:A:Purger rename _add_timeline_event to _finalize_purge
D:D:A:Purger extract _update_allocation_status
Remove unused include.
Test that the correct columns are "extra".
move get_trash_folder functionality to D:Volume
D:Volume have database select trash volume by aggr