gpgv: add a gpgv command
gpgv: add a gpgv command

usage
gpgv [-v] keyring signature file

There doesn't seem to be a way to do this in the domain of the crypto
package, or did I miss something?

Signed-off-by: Ronald G. Minnich <f569d0af9a3481c4007b95c7180d6c41009f2513@google.com>

u-root/u-root,GanShun/u-root,rminnich/u-root,hugelgupf/u-root,GanShun/u-root,hugelgupf/u-root,rminnich/u-root,GanShun/u-root,hugelgupf/u-root,rminnich/u-root,u-root/u-root,rminnich/u-root,hugelgupf/u-root,u-root/u-root