[PATCH 0/6] MR6537: Cmd engine rewrite (part XXV)

[eric pouech (＠epo)]

This is part XXV of command engine rewrite.

This MR tackles three items:
- fixing some corner cases in variable expansion. Note, there's
  still todo_wine in the non regression tests, but I don't feel
  like fixing them for now (like an un-paired ! within double quotes
  when delayed expansion is enabled - which behaves differently
  then not within double quotes)
- breaking out of FOR loops with 'EXIT /B'. I'm damn sure I
  dealt with this earlier on, it likely fails into the cracks
  during some rebase.
- somme builtin commands behave differently when run from .BAT
  or .CMD files.