nvda

8306a560 - Sapi4 synthDriver: fix so it works with comtypes 0.6.2, and its probably safer anyway. Specifically: never hold around an actual Python implementation of a comtypes COMObject directly, instead queryInterface striaght away to one of the interfaces it supports. In this case, _bufSink is now an ITTSBufNotifySink COM pointer, rather than a direct instanciation of our implementation. This stops us from having to access COMObject._com_pointers_ (which should be private), plus in comtypes 0.6.2 this dictionary gets cleared when the object's refcount gets to 0.