merge bugfix: show test failures

Dependencies

• [2] 36Z442IV back to commit 8123959e52f without code editing
• [*] 3QNOKBFM beginnings of a test harness
• [*] AVTNUQYR basic test-enabled framework

Change contents

• edit in app.lua at line 16
  [5.2302]

  [2.8444]
  + Test_errors = {}
• edit in app.lua at line 18
  [2.8462]

  [2.8462]
  + if #Test_errors > 0 then

  + error('There were test failures:\n\n'..table.concat(Test_errors))

  + end