Revert infinite scroll in timelines back to looking at ID of oldest

loaded status; do not preload submitted statuses into community/public
timelines, unless those timelines have already been loaded; do not
close streaming API connections for community/public timelines, once
they have been established (most users navigate back to them eventually)

app/assets/stylesheets/components.scss

@@ -576,6 +576,7 @@ a.status__content__spoiler-link {
     color: $color1;
     overflow: hidden;
     text-overflow: ellipsis;
+    white-space: nowrap;
 
     &:focus {
       outline: none;