keep repeated cursor up/down motions from drifting left

Dependencies

• [2] BULPIBEG beginnings of a module for the text editor
• [3] DFSDPDO7 bugfix
• [4] 5Q6NIG66 bugfix

Change contents

• replacement in text.lua at line 1111
  [2.1053]→[2.1053:1071](∅→∅)
  − return curr
  [2.1053]

  [2.1071]
  + if x-currxmin < currxmax-x then

  + return curr

  + else

  + return curr+1

  + end