Renames a bunch of timings to be more appropriate for the new environment.
Many things dealt with sync loads which wasn't correct anymore.
adjusted timings to be a little bit more accurate here.
Also cleaned up old 1.13 async chunks configs so people won't keep
thinking they can change some of those configs when they can't.
We still keep vanilla process of waiting for existing session to be removed before logging in
by storing a separate map of pending.
also fire the callback using executor incase further recursion causes any trouble
