Raise an exception when the specified cipher suite is not available

Motivation:

SSL_set_cipher_list() in OpenSSL does not fail as long as at least one
cipher suite is available.  It is different from the semantics of
SSLEngine.setEnabledCipherSuites(), which raises an exception when the
list contains an unavailable cipher suite.

Modifications:

- Add OpenSsl.isCipherSuiteAvailable(String) which checks the
  availability of a cipher suite
- Raise an IllegalArgumentException when the specified cipher suite is
  not available

Result:

Fixed compatibility