* dtls/openssl.py:
- Added methods SSL_CTX_set_info_callback(), SSL_state_string_long(), SSL_alert_type_string_long() and SSL_alert_desc_string_long()
- Added constants for state and error evaluation during callback
* dtls/sslconnection.py: Added _ssl_logging_cb() as default callback function - only outputs messages when logger is active
* dtls/openssl.py: SSL_write() can handle ctypes.Array data
* dtls/sslconnection.py: Added missing import ERR_BOTH_KEY_CERT_FILES
* dtls/test/simple_client.py: Added basic test client to use with dtls/test/echo_seq.py
* dtls/openssl.py:
- Ordered constants according to header file from openSSL
- Beautified __all__-list and map for _make_function() in order to easy merges in the future
- Added a few returns in order to evaluate the success of the called methods
* dtls/patch.py: Grouped imports in the following order - system, local
* dtls/sslconnection.py: ssl protocol not hardcoded anymore for forked objects
* dtls/x509.py: logger messages working again