clean up some final bifold code

source_file.lua

@@ -1,7 +1,5 @@
 -- primitives for saving to file and loading from file
 
-Fold = '\x1e'  -- ASCII RS (record separator)
-
 function file_exists(filename)
   local infile = App.open_for_reading(filename)
   if infile then
@@ -28,13 +26,7 @@ function load_from_file(infile)
       if line == '```lines' then  -- inflexible with whitespace since these files are always autogenerated
         table.insert(result, load_drawing(infile_next_line))
       else
-        local line_info = {mode='text'}
-        if line:find(Fold) then
-          _, _, line_info.data, line_info.dataB = line:find('([^'..Fold..']*)'..Fold..'([^'..Fold..']*)')
-        else
-          line_info.data = line
-        end
-        table.insert(result, line_info)
+        table.insert(result, {mode='text', data=line})
       end
     end
   end
@@ -54,10 +46,6 @@ function save_to_disk(State)
       store_drawing(outfile, line)
     else
       outfile:write(line.data)
-      if line.dataB and #line.dataB > 0 then
-        outfile:write(Fold)
-        outfile:write(line.dataB)
-      end
       outfile:write('\n')
     end
   end
@@ -147,11 +135,7 @@ function load_array(a)
     else
 --?       print('inserting text')
       local line_info = {mode='text'}
-      if line:find(Fold) then
-        _, _, line_info.data, line_info.dataB = line:find('([^'..Fold..']*)'..Fold..'([^'..Fold..']*)')
-      else
-        line_info.data = line
-      end
+      line_info.data = line
       table.insert(result, line_info)
     end
   end

source_undo.lua

@@ -61,7 +61,7 @@ function snapshot(State, s,e)
   for i=s,e do
     local line = State.lines[i]
     if line.mode == 'text' then
-      table.insert(event.lines, {mode='text', data=line.data, dataB=line.dataB})
+      table.insert(event.lines, {mode='text', data=line.data})
     elseif line.mode == 'drawing' then
       local points=deepcopy(line.points)
 --?       print('copying', line.points, 'with', #line.points, 'points into', points)