Refactored use of async. (#215)

* Refactored use of async. No tight while-loops but instead using await and continue on background threads.

* Remove use of .Wait() to avoid potential deadlocks. increase use of ConfigureAwait, and remove await where not needed

* Simplified async code. Instead of forwarding to tasks and have to switch to ui thread, it's easier to just await and continue on the same thread here.