Misc Deuce TODOs

[ravichugh]

• X button in pop-up windows (deuce, right-click, config panel).

• Restore Deuce selection state on Undo.

• Issue with text-selection. Hold Shift and press an arrow key to perform an Ace text selection. A Deuce polygon appears.

• (let p e1 e2) target positions: The whitespace between p and e1 is treated specially, with all characters up to the first newline (if any) dedicated to after-p, and the rest to before-e1. Instead, each polygon should be mapped to a set of code objects (specifically, white space objects in this case), and selection sets should be interpreted as the Cartesian product of the selected code object sets.

[justinlubin]

Moved to individual issues in project board.