verify-tag: add option to print raw gpg status information
verify-tag by default displays human-readable output on standard error.
However, it can also be useful to get access to the raw gpg status
information, which is machine-readable, allowing automated
implementation of signing policy. Add a --raw option to make verify-tag
produce the gpg status information on standard error instead of the
human-readable format.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>