Improve the error message when hostname verification fails

When hostname verification fails org.apache.http.conn.ssl.SSLConnectionSocketFactory will throw a SSLPeerUnverifiedException with a message like this:

Host name 'FOO' does not match the certificate subject provided by the peer (CN=BAR)

Expected:
Including the subject alternative names, rather than the CN, in the message would be a lot more helpful when troubleshooting (and probably more correct since the use of CN matching is deprecated through RFC 2818).