regression: couldn't do many drawing operations because line.y was reset

Dependencies

• [2] LS55YKGW switch copy/paste to ctrl- hotkeys
• [3] 5FW7YOFT highlight selection while dragging
• [4] XNFTJHC4 split keyboard handling between Text and Drawing
• [5] AVTNUQYR basic test-enabled framework
• [6] OYXDYPGS get rid of debug variables
• [7] JCSLDGAH beginnings of support for multiple shapes
• [8] Z4XRNDTR find text
• [9] ESETRNLB bugfix: printing the first part of a line at the bottom made it seem non-wrapping
• [10] YTSPVDZH first successful pagedown test, first bug found by test
• [*] BULPIBEG beginnings of a module for the text editor
• [*] HOSPP2AN crisp font rendering
• [*] OTIBCAUJ love2d scaffold
• [*] NQWWTGXR switch undo/redo to ctrl- hotkeys

Change contents

• edit in text.lua at line 890
  [13.4058]

  [13.4058]
  + line.y = nil
• edit in main.lua at line 255
  [4.1550]→[3.1746:1823](∅→∅)
  − for _,line in ipairs(Lines) do line.y = nil end -- just in case we scroll
• edit in main.lua at line 292
  [15.100]

  [15.100]
  + for _,line in ipairs(Lines) do line.y = nil end -- just in case we scroll
• edit in main.lua at line 302
  [15.388]

  [15.388]
  + for _,line in ipairs(Lines) do line.y = nil end -- just in case we scroll
• edit in main.lua at line 313
  [2.90]

  [2.90]
  + for _,line in ipairs(Lines) do line.y = nil end -- just in case we scroll
• edit in main.lua at line 319
  [2.202]

  [2.202]
  + for _,line in ipairs(Lines) do line.y = nil end -- just in case we scroll
• edit in main.lua at line 325
  [2.318]

  [2.318]
  + for _,line in ipairs(Lines) do line.y = nil end -- just in case we scroll
• edit in main.lua at line 363
  [4.3882]

  [4.4979]
  + -- DON'T reset line.y here
• edit in main.lua at line 393
  [4.5022]

  [4.5022]
  + for _,line in ipairs(Lines) do line.y = nil end -- just in case we scroll