Log Message:
Update to 2.0.21:

Noteworthy changes in version 2.0.21 (2013-08-19)
-------------------------------------------------

 * gpg-agent: By default the users are now asked via the Pinentry
   whether they trust an X.509 root key.  To prohibit interactive
   marking of such keys, the new option --no-allow-mark-trusted may
   be used.

 * gpg-agent: The command KEYINFO has options to add info from
   sshcontrol.

 * The included ssh agent does now support ECDSA keys.

 * The new option --enable-putty-support allows gpg-agent to act on
   Windows as a Pageant replacement with full smartcard support.

 * Support installation as portable application under Windows.