Improvements and bugfix to PyS2OPC, following interoperability tests with UA Gateway
Closes #554 (closed), #555 (closed), #556 (closed), #558 (closed), #559 (closed). Contributes #557 (closed)
Closes #554 (closed), #555 (closed), #556 (closed), #558 (closed), #559 (closed). Contributes #557 (closed)