Log Message:
Update etach to 1.2.9.  Changes since 1.2.6:

1.2.9

Documentation update.  (Note: Include the word "etach" somewhere in
the "Subject:" line of any email sent to the author or your message
may be discarded by the mail filter.)

1.2.8

Changed documentation strings to better conform to "Tips for
Documentation Strings" in GNU Emacs Lisp Reference Manual per
suggestion by rms.

1.2.7

Changed the detachment-default-directory portion of the mime-decode
algorithm to treat DOS/Windows drive letter prefixes (e.g., "C:") as
valid starts of absolute path names.  This addresses a couple of
Windows user requests.

Added user-customizable variable "etach-write-text-files."  This
addresses a user request.

Adapted the comment marks (semicolons) to convention.