Enhancement request: bulk update monsters

[pbaranay]

It would be great to have an interface to change the priority of monsters en masse (perhaps bulk delete monsters as well). I'm envisioning something like checkboxes next to each monster, plus a new button at the top that says "Bulk update monsters" and, upon click, presents you a dialog to select a new priority for the monsters.

This is a somewhat rare operation, and checkboxes next to each monster could be unattractive, so it probably shouldn't be shown all the time.

Thanks for maintaining this great resource!