Version 3.5.0

• Error trapping reworked: ServerLoop, WaitForData, OnServerTimeout and TrapRequest act on
  HandleError's signal (#.ErrorParms.signal) and cut back to Rumba's own handler.
  OnServerTimeout now follows the lead of ServerLoop.
• New method GetConnectionOfThread; connections keep the last block received in LastBlock.
  Together they allow a crash handler to save the offending request.
• House keeping now runs once the interval (CongaTimeout) has passed, not only when the server
  has been idle for a full interval: a busy server never ran it at all. See HouseKeepingIfOverdue.
  The interval is measured to the millisecond (SecondsNow), and putting the clock back no longer
  suspends house keeping.
• The 819⌶ fallbacks are gone: 18.2 has ⎕C.
• Tests added: TestHouseKeepingWhenBusy, TestRequestTargetNotSimple & TestGetConnectionOfThread.
  (The test server now runs with a CongaTimeout of one second and counts its house keeping)
• Bug fixes
  • ErrorInRumba logged the error caption twice.
  • A "RequestTarget" that is not simple character data is now refused with a DOMAIN ERROR by Send,
    SendAndReceive and SendExpect100, before a connection is opened. It used to be composed into a
    request line no server can parse, which left the client waiting for a reply that never came,
    looking like a hang
• Note that RumbaLean is no longer kept in sync with Carlisle's Rumba; "HowToSyncWithRumba.md" is gone.