v2.20.02b2

• if a publish fails, retry forever, do not give up (result of major
  outages) probably fixing a regression.
• added exponential backoff to publish retries.
• improved testing on travis (unit tests, static flow, dynamic flow) more to
  come.
• sr.py now prints an error message when it fails to find an include file
  (used to crash.)
• extraneous log messages cleaned up.
• catch a timeout exception that happens when the app is sleeping, not a
  bige problem, not worth a major error message (sr_poll)
• if we get a message about a newer version of a file, call it new if
  mtime is newer, or if checksum is useless (0, random, name) use
  checksum as last resort.