I de-cluttered the editor menu, in a couple ways:

• I made the player-selection widget collapsible, collapsed by default. To make sure  gamepad connect/disconnect updates still got reflected in collapsed-mode, I refactored a lot of DOM UI stuff, and now it's generally easier to wire data updates to DOM updates in the code.
• I moved all the verb-buttons to an action-bar at the bottom, which responds to the selected item's state. And I added the whole "selection" feature. It makes adding verbs easy; I'll be adding more soon, to make it possible to re-order things.