make space for multiple kinds of width

Dependencies

• [2] 2KRK3OBV don't rely on defaults
• [3] G77XIN7M selecting a stroke
• [4] MNWHXPBL more lightweight; select just the stroke at the mouse
• [5] NZ7V4BVS note card
• [6] 6LJZN727 handle chords
• [7] IZZVOCLB confirm that we have access to all of the love API
• [8] XX7G2FFJ intermingle freehand line drawings with text
• [9] OTIBCAUJ love2d scaffold

Change contents

• replacement in main.lua at line 7
  [3.13]→[4.14:47](∅→∅),[4.14]→[4.14:47](∅→∅)
  − width, height, flags = 0, 0, nil
  [4.14]

  [4.2]
  + screenw, screenh, screenflags = 0, 0, nil
• replacement in main.lua at line 13
  [4.136]→[4.136:183](∅→∅)
  − width, height, flags = love.window.getMode()
  [4.136]

  [2.2]
  + screenw, screenh, screenflags = love.window.getMode()
• replacement in main.lua at line 20
  [4.243]→[4.243:302](∅→∅)
  − love.graphics.rectangle('fill', 1, 1, width-1, height-1)
  [4.243]

  [4.302]
  + love.graphics.rectangle('fill', 1, 1, screenw-1, screenh-1)