[PATCH 0/7] MR6116: Cmd engine rewrite (part XXII)

[eric pouech (＠epo)]

This is part XXII of cmd.exe engine rewrite.

It tackles bug id 55151. The root cause is that native doesn't
keep the batch/command file opened while processing each command
in that file.

This allows:
- the batch file to delete itself (described in here above mentionned
  bug report)
- but also to modify the batch file on the fly...

Quite a bit of refactoring to no longer depend on the file handle as
a reference the batch file.