Fix for null ref exception in Service Bus scale-out:
- The ConnectionContext is now created immediately and passed in to the Subscribe call for initialization, so it should never be null
- #2933
Fixes null ref errors in Service Bus scale-out:
- Handle when the factory creation fails in the ServiceBusConnection ctor
- Handle when topics are never created and then are attempted to be closed in Dispose
- #2937
Merge branch 'release' into dev
Queuing messages when scaleout stream is in initial state

#2767
Temporary table for new PayloadId is removed
Made changes as per code review feedback

#2767
Made changes as per code review feedback

#2767
Addressed code review comments
Cleaned up queuing changes in scale-out:
- Moved QueuingBehavior enum to root namespace
- Updated doc comments
- Changed logic in ScaleoutStream.Send when waiting on drain task to be more careful RE null refs
Updated scale-out stream unit tests:
- Added some more tests to verify behavior of queuing behavior
Merge branch 'release' into dev
Throw configuration exception in service bus

#2948
Removed Lazy initialization for Service Bus

#2948
Merge branch 'release' into dev
Updated versions for 2.2.0-pre
Merge pull request #2939 from AlexeyRokhin/dev

Temporary table for new PayloadId is removed
Forever Frame JS client now runs received payloads through custom JSON if configured:
- Capture the original JSON for the connection
- In FF transport, if current JSON !== original JSON (custom set) then stringify using original JSON and parse using custom JSON
- Added JS unit tests to cover new behavior
- Corrected hubs.js version in samples project
- #2945
Address review feedback & added samples code:
- #2945
Fix version in hubs.js
Server changes to support long-polling keep alives

#1781