* dtls/__init__.py: Added DtlsSocket() from wrapper and aliases for wrap_server() and wrap_client()
* dtls/err.py: Added patch_ssl_errors() to patch ssl-Module with ERR_* constants
* dtls/patch.py: Patched ssl-Module with SSL_BUILD_* constants and added call to patch_ssl_errors()
* dtls/wrapper.py:
- Added a server and client function to alias/wrap DtlsSocket() creation
- Cleanup of DtlsSocket.__init__()
- Cleanup of exception handling in all member methods
- Cleanup sendto() from client: no endless loop and first do a connect if not already connected
* dtls/test/unit_wrapper.py: Adopt the changes made described above