Add debugging messages
Rename engine variables to 'eng' for consistency
Container.LS(): return a list of filenames at the target directory
Only intercept sigkill and sigint
Remove redundant code left behind refactor
Make sure the root container has id 0. CurrentContainer() allows introspection.
Typos and debugging
docker build pseudo-implementation
Print an error on uknown command
OP with no argument is legal
Use Cmd.Run() instead of Start() and Wait()