Sets the app version if possible

This sets the app version to something that is hopefully always
sensible!

Ive also included the release stage change on this branch too (I hate github for windows!)
If it turns out we dont want to publish that yet I can revert that change on this branch and re-push
What we can do here is set/leave AppVersion as null. The payload gets through OK and they wont be able to filter by AppVersion but this is more explicit. Guessing its 1.0 could be confusing for some people. I'll make the change now!