In order to keep deleted items for a while, the periodic task can now
use a duration to only remove items with a certain age. This can be
used to ensure that a deleted item stays at least X days before it
will be removed from the database.
Refs: #347
It's not very likely to have more modes of search besides normal and
trashed, but got surprised in that way quite often and it's nicer this
way anyways.
A new query/request parameter can be used to apply a search to only
soft-deleted items.
The query expression `Trashed` has been introduced which selects only
items with state `Deleted`. This is another option an analog to
`ValidItemStates` (both cannot be used together as they would select
no items). This new query node is not added to the parser, because
users may not use it in their own queries - it must be part of the
"fixed" query so the application can control in which subset to search
(it would otherwise be possible to select any items).
When deleting items via the http api, they are not deleted anymore but
a new status "Deleted" is set. The collective insights contains now a
count separately for deleted items.
It doesn't make much sense to have this per collective, because this
is triggered by an admin after changing the server config file. So it
is now implemented as an admin endpoint that affects all files.
If multiple tags of the same category are applied to the same item,
just summing tag counts will produce the wrong results as now items
are counted multiple times.
When reprocessing an item, the metadat of all *files* are replaced.
This change now also sets some metadat to an item, but only if the
item is not in state "confirmed". Confirmed items are not touched, but
the metadata of the files is updated.
