Caliburn Micro 4.0.62-alpha

This alpha marks a major milestone. I believe most of the breaking changes required to support an async first model are now in place.

The versioning number system has change a little, but this makes it easier to have packages available from the CI system.

This affects also every type in Calburn.Micro including but not limited to the following:

• IWindowManager
• IEventAggregator
• IActivate
• IDeactivate
• IConductor
• IGuardClose

These changes were long overdue and help to better support view model life cycles where async operations are happening and especially in IGuardClose where async dialogs are often used.

I understand this represents a large amount of breaking changes, however the nature of these changes tend be quite simple (returning Task.CompletedTask for instance).

The migration docs will be updated soon.