move default file location

Dependencies

• [2] ZJOSQFN6 bugfix: path munging on Windows
• [3] 2L5MEZV3 experiment: new edit namespace
• [4] UHB4GARJ left/right margin -> left/right coordinates
• [5] LF7BWEG4 group all editor globals
• [6] TGZAJUEF bring back a set of constants

Change contents

• replacement in edit.lua at line 97
  [3.3539]→[2.496:597](∅→∅)
  − filename = love.filesystem.getUserDirectory()..'/lines.txt', -- '/' should work even on Windows
  [3.3539]

  [3.97660]
  + filename = love.filesystem.getSourceBaseDirectory()..'/lines.txt', -- '/' should work even on Windows