Add "Delete" button to "Configure block" screen

For enhanced usability and for consistency with the content editing process already in place with the node system, I believe the "Configure block" screen should have a "Delete" button on it. If you come to a block from the block admin screen then it only makes sense you would you use "Delete" link in the operations column; but if you use, for example, Block Edit module or a Zen-based theme, you are likely to come to the task by clicking on the hover "Edit" link on a block display itself, resulting in a confusing and obtrusive interruption to the natural flow when there's no delete button on that screen.