[PATCH 0/7] MR6041: Cmd engine rewrite (part XIX)

[eric pouech (＠epo)]

This is part XIX of cmd engine rewrite.

It's the last MR (for now) for setting success/failure
return code on internal commands.

The remaining todo in this area are due to:
- incompletly implemented builtin (eg: TYPE not handling
  multiple files, not wildcards; CHOICE missing a bunch
  of features; ...),
- some commands (like START) being implemented as external
  executables, hence forcing RETURN CODE = ERRORLEVEL
  which is not always wanted,