bug: qpush loses loses file executable permissions

[Armando Singer]

> I'm saying this because I commonly use Mercurial for my own personal
> work, and then export diffs which are applied with gpatch(1) on Perforce
> workspaces.  Using --git format patches by default in MQ would break
> this, and I would have to *disable* --git patches to make them usable
> for this sort of workflow.

This sounds like a nice-to-have. One could turn off the git diff
setting before exporting when working with an external tool (or use
mpatch).

On the other hand, IMO, keeping file mode info, etc. within hg/mq is
fundamental. One should not have to think about whether one only wants
to perform certain operations on plain text vs do anything that hg
supports. It should either "just work" with no extra config, or (for
backward compatibility), at least warn of possible data loss.

Also, since this setting is external, I need to ensure that everyone
makes this change to her .hgrc. Without the above, we have another
thing on the checklist when debugging problems for a team of many
developers spread across multiple offices.

Armando