Update to 7.21.3:

Changes:

    * Added --noconfigure switch to testcurl.pl
    * Added --xattr option
    * Added CURLOPT_RESOLVE and --resolve
    * Added CURLAUTH_ONLY
    * Added version-check.pl to the examples dir

Bugfixes:

    * check for libcurl features for some command line options
    * Curl_setopt: disallow CURLOPT_USE_SSL without SSL support
    * http_chunks: remove debug output
    * URL-parsing: consider ? a divider
    * SSH: avoid using the libssh2_ prefix
    * SSH: use libssh2_session_handshake() to work on win64
    * ftp: prevent server from hanging on closed data connection
      when stopping a transfer before the end of the full transfer
      (ranges)
    * LDAP: detect non-binary attributes properly
    * ftp: treat server's response 421 as CURLE_OPERATION_TIMEDOUT
    * gnutls->handshake: improved timeout handling
    * security: Pass the right parameter to init
    * krb5: Use GSS_ERROR to check for error
    * TFTP: resend the correct data
    * configure: fix autoconf 2.68 warning: no AC_LANG_SOURCE call detected
    * GnuTLS: now detects socket errors on Windows
    * symbols-in-versions: updated en masse
    * added a couple examples that were missing from the tar ball
    * Curl_send/recv_plain: return errno on failure
    * Curl_wait_for_resolv (for c-ares): correct timeout
    * ossl_connect_common: detect connection re-use
    * configure: Prevent link errors with --librtmp
    * openldap: use remote port in URL passed to ldap_init_fd()
    * url: provide dead_connection flag in Curl_handler::disconnect
    * lots of compiler warning fixes
    * ssh: fix a download resume point calculation
    * fix getinfo CURLINFO_LOCAL* for reused connections
    * multi: the returned running handles conuter could turn negative
    * multi: only ever consider pipelining for connections doing HTTP(S)

(wiz)