improved:
1) flags on left side for easy left-anchor grep'ping
2) authority flag shares exit flag column
3) "a" alpha and "r" rc appended to version
4) OS flag in separate aligned column
NOTES
no "directory" flag since dir-port is "none" when not present
no "valid" or "running" flags since such routers are excluded from the ranking
Blutmagie has a "x" flag for "bad exit", no HDdir flag
Rueckgr has a "h" HDdir flag, but no "bad exit" flag