On svn-auth-x509 branch, restore the fingerprint output for certs.

* subversion/include/svn_x509.h
  (SVN_X509_CERTINFO_KEY_SHA1_DIGEST): New constant.

* subversion/libsvn_subr/x509parse.c
  (svn_x509_parse_cert): Calculate the SHA1 fingerprint and store it in the
    certinfo hash.

* subversion/svn/auth-cmd.c
  (show_cert): Display the SHA1 fingerprint.

* subversion/tests/libsvn_subr/x509-test.c
  (x509_test): Add a sha1_digest field.
  (cert_tests): Add digests for the certificates.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/svn-auth-x509@1606262 13f79535-47bb-0310-9956-ffa450edef68