Log Message:
Update elm to 2.5.7. Changes are bugfixes only.

Changes in 2.5 PL7

- a few display issues fixed (from Kenneth Reek)

- buffer overflow in frm fixed

Changes in 2.5 PL6

- Fixed message-id in the In-Reply-To header.

- Actually show the -r option in the usage

- Whacked a few more places where we might follow a symlink in tmpdir

- Fastmail didn't grok commas correctly.

- Change lock.c to not use errno unless there's an errno