Improvements to detail dialogs

This page is a capture in the next bucket of the product backlog — a pre-sprint idea, not yet pulled into a sprint as a story.

We've implemented most of these but check:

• For most dialogs, pressing escape should be the same as closing it.
• We should also add a "cancel" button to dialogs, makes it a bit more "normal".
• New dialogs use toolbars instead of buttons at the bottom.