remove some support for long lines from source editor

Dependencies

• [2] G54H3YG2 get rid of all bifold text
• [3] KKMFQDR4 editing source code from within the app
• [4] OI4FPFIN support drawings in the source editor
• [*] BULPIBEG beginnings of a module for the text editor
• [*] 242L3OQX bugfix: ensure Cursor_line is always on a text line

Change contents

• edit in text.lua at line 620
  [7.226]

  [7.226]
  + if State.cursor1.pos == nil then

  + State.cursor1.pos = 1

  + end
• replacement in source_text.lua at line 432
  [3.108390]→[2.2497:2660](∅→∅),[2.2660]→[3.108390:108443](∅→∅),[3.108390]→[3.108390:108443](∅→∅),[3.108443]→[2.2661:2754](∅→∅),[2.2754]→[3.108443:108572](∅→∅),[3.108443]→[3.108443:108572](∅→∅),[3.108572]→[2.2755:2842](∅→∅),[2.2842]→[3.108659:108665](∅→∅),[3.6889]→[3.108659:108665](∅→∅),[3.108659]→[3.108659:108665](∅→∅)
  − -- If a line/paragraph gets to a page boundary, I often want to scroll

  − -- before I get to the bottom.

  − -- However, only do this if it makes forward progress.

  − local bot2 = Text.to2(State, State.screen_bottom1)

  − if bot2.screen_line > 1 then

  − bot2.screen_line = math.max(bot2.screen_line-10, 1)

  − end

  − local new_top1 = Text.to1(State, bot2)

  − if Text.lt1(State.screen_top1, new_top1) then

  − State.screen_top1 = new_top1

  − else

  − State.screen_top1 = {line=State.screen_bottom1.line, pos=State.screen_bottom1.pos}

  − end
  [3.108390]

  [3.108665]
  + State.screen_top1 = {line=State.screen_bottom1.line, pos=State.screen_bottom1.pos}
• edit in source_text.lua at line 678
  [3.10848]

  [3.10848]
  + end

  + if State.cursor1.pos == nil then

  + State.cursor1.pos = 1