Read Hacker News top-comments in right-sidebar with DOM node construction (no innerHTML).
1) Allows viewing of top comments in right-sidebar for quick understanding of HN responses to any HN item.
2) Reply counts shown and they can be opened if they exist.
3) Right-click anywhere to close sidebar, ESC or bottom 'X'.
4) Sidebar width retained between sessions.
5) Usernames link to their underlying comment.
6) Comment body links remain clickable.
7) Truncate button (or spacebar) for sidebar pruning as alternative to scrolling.
8) Marking of sidebar items already read with state persistence across sessions.
9) Untruncated comment counts
