Some more menu stubs

Signed-off-by: Daniel Borchmann <daniel.borchmann@mailbox.tu-dresden.de>
Fix get-repl-thread

Signed-off-by: Daniel Borchmann <daniel.borchmann@mailbox.tu-dresden.de>
Fix layout of error window from with-swing-error-msg

Signed-off-by: Daniel Borchmann <daniel.borchmann@mailbox.tu-dresden.de>
Improve error reporting in GUI

Signed-off-by: Daniel Borchmann <daniel.borchmann@mailbox.tu-dresden.de>