delete some dead code

Dependencies

• [2] ME7WBLF5 bugfix: log filenames can have 2 formats
• [3] W6XUYQKP source: show files in MRU order
• [4] 6DYSB5DY bugfix: perform matches in the right order
• [5] KKMFQDR4 editing source code from within the app
• [6] N7VXEGLG yet another bugfix in log parsing
• [7] ZTK4QTZT extract a couple of functions
• [8] AIBA4RWQ hide cursor in log browser window

Change contents

• edit in log_browser.lua at line 38
  [2.266]→[4.193219:193269](∅→∅),[4.193219]→[4.193219:193269](∅→∅)
  − line.filename = guess_source(line.filename)
• edit in log_browser.lua at line 75
  [4.194585]→[4.194585:194782](∅→∅)
  − end

  −

  − function guess_source(filename)

  − local possible_source = filename:gsub('%.lua$', '%.splua')

  − if file_exists(possible_source) then

  − return possible_source

  − else

  − return filename

  − end
• replacement in commands.lua at line 132
  [3.58]→[4.85:164](∅→∅),[4.85]→[4.85:164](∅→∅)
  − local candidate = guess_source(s..'.lua')

  − source.switch_to_file(candidate)
  [3.58]

  [4.164]
  + source.switch_to_file(s..'.lua')