change cursor bounds check slightly

Dependencies

• [2] ELJNEPW2 simplify cursor-on-screen check
• [3] YJJ4X4JG bugfix: avoid scrolling on 'end'
• [4] LF7BWEG4 group all editor globals
• [5] WLJCIXYM add state arg to a few functions
• [*] BULPIBEG beginnings of a module for the text editor

Change contents

• replacement in text.lua at line 939
  [2.223]→[3.234:247](∅→∅),[3.912]→[3.234:247](∅→∅),[3.234]→[3.234:247](∅→∅)
  − App.draw()
  [2.223]

  [2.224]
  + edit.draw(State)