Generate list of acceptable mime types for cover art from the list in the database (MBS-7513)
MBS-7519: Remove z-index from PDF info tag

The tag marking thumbnails of PDF cover art had a z-index of 1000 with
the intention of layering it on top of the actual thumbnail. This made
it cover both the artwork viewer overlay and the pull-down menu,
however.

In fact, the z-index wasn't necessary at all, because positioned
elements (such as the "PDF" tag) are always layered on top of
non-positioned elements (such as the image thumbnail). It is therefore
removed.
MBS-7516: Show an age of 0 in user profiles

The age was displayed in user profiles based on its truth value
instead of its definedness, thus excluding the value "0".
MBS-6181: Disallow nominating a deleted user for auto-editor
MBS-7514: Reject user name "Deleted Editor #..."

A name of the form "Deleted Editor #123456" for a regular user is not
only confusing, but also prevents the account with ID 123456 from
being deleted, because the account renaming will fail. This applies to
other case variants, too, as the unique index on editor.name is case
insensitive. Therefore, this change makes the server reject
registration attempts for names of the type "Deleted Editor #...".
Add test for MBS-7514
MBS-6309: Show all-0 score column in search results

The score column on release search result pages was accidentally not
displayed when the topmost entry on the page had a score of 0. Fix
this by checking for definedness instead of the truth value.
Add test for registering an existing user name
Fix titles of two account registration tests
Show link order in "add relationship" edit display
Add more series relationships to the URL matching
Add missing series triggers
Make sure you can't select grouping link types in the RE
Don't create empty URL edits in the release editor (client-side half of MBS-7545)
MBS-7533: Allow creating a series from inline search
MBS-7354: Avoid ISE when a relationship has vanished

A relationship that was included in an entity edit form (mini
relationship editor) may have disappeared when the form is finally
submitted, namely if an edit to remove it has been applied or the edit
creating it has been cancelled in the meantime.

The controller did not anticipate this possibility and always expected
a relationship with known ID to exist. Hence, it would call a method
for an undefined relationship object, causing an internal server
error. This is avoided by exiting the loop iteration whenever a
(previously existing) relationship cannot be loaded.
MBS-7543: "Cancel" does not revert instrument changes

Add a .peek() to avoid the computed in bindingHandlers.instrumentSelect
from reevaluating after instruments are changed.
MBS-7548: reorder series automatically correctly even if some text values are duplicated
MBS-7532: Ignore pasted MBIDs that don't match the entity type of any selectable link type
Allow seeding URLs without link types again