Rework problem detection and restart logic

* Be willing to start dump1090 if it's not running after a fairly long while

* Allow /etc/init.d/*dump1090* startup type (restart, start) to be specified

* Cancel prior timer events for scheduling FA-style port connecting

* Rename faup1090_messages_being_received_check to adsb_messages_being_received_check

* Add new -debugport option to allow localhost telnetting to Tcl interpreter for poking around and debugging.