Dragging from trash/save should cancel trash/save instead of dragging node

When you press (but don't release) on the trash/save buttons, but want to cancel, you can't cancel by moving the mouse outside the button; instead, it drags the node around. This is contrary to typical UI design where dragging off a pressed-but-not-released button cancels clicking the button, and causing no other effects.

Ideal behavior would be that dragging can only be initiated from click-dragging the node, but not when click-dragging from a trash/save button.

The same should apply to expand/collapse.

Hitting Esc should also cancel any unfinished operation. This works for dragging, but not for clicking buttons.