Prevent mouseup from turning into a click

Mouseup was turning into a click on whatever was the last thing clicked.
In this walkthrough, this would sometimes be the "Add Area" mode button,
which would re-enter the add area mode and throw away the user's drawing.
(I have no idea why.)

modules/behavior/draw.js

@@ -141,6 +141,8 @@ export function behaviorDraw(context) {
         d3.select(window).on('keyup.space-block', function() {
             disableSpace = false;
             d3.select(window).on('keyup.space-block', null);
+            d3.event.preventDefault();
+            d3.event.stopPropagation();
         });
 
         d3.event.preventDefault();