In cases where a VST3 plugin set a non-zero latency in its
prepareToPlay, and then set its latency to 0 later on, the host was not
notified about the latency change.

In older versions of the VST3SDK, hostContext is a raw pointer,
in newer versions it's a smart pointer. If we do manual
refcounting with the smart pointer, we may cause leaks.

Accessibility:  Fixed some bugs in Windows text navigation and readouts, improved selection and focus navigation