timeline bug fixes plus tests, and one sliding sync fix for #1324 #1540

7w1 merged 9 commits into

fix/sliding-sync-stale-invite-after-joinSableClient/Sable:fix/sliding-sync-stale-invite-after-joinfrom

fix/timeline-unread-and-sync-loadingSableClient/Sable:fix/timeline-unread-and-sync-loadingCopy head branch name to clipboard