JOIN is now compliant

- Update README.md
- dropped useless user flags
- Started work on STATS command
- Transitioned some timekeeping functions from System.currentTimeMillis
to Util.getMicroTime which takes System.nanoTime and divides by 1m to
get MicroTime.
- Added more replies to the formatter
- Tried to collect bytes in/out stats but failed. Leftover code from
this attempt is still included for future consideration.