FREEZE: Transfer with No Objects Selected and Unreal Closed

[Donovan Keith]

1. Open C4D
2. Create a scene w/ some objects
3. Plugins > C4D to UE4

FREEZE

C4D is non-responsive for 30+ seconds (I assume while it's trying to make a connection).

Expected:

1. Connection and transfer doesn't block the main thread.
2. Status bar updates with progress, perhaps a message like "Attempting to connect to UE4" and a progress bar that updates showing progress towards timeout.
3. Esc key will cancel the connection attempt.