I noticed on one particular system that Canceling or Completing
the configuration wizard on a fresh install, sbbsctrl.exe would
just shut down (no error dialog or anything, likely a crash of
some kind). Instrumenting StartupTimerTick() didn't reveal anything
useful (it ran to completion).

By changing the method of launching the Configuration Wizard,
I was able to eliminate this observed problem. Now, the StartupTimer
runs twice on a fresh install (just once for a normal startup),
and the second run of the StartupTimerTick starts the configuration
wizard.

I also reverted to the previous behavior of dynamically creating
and destroying the wizard for each use. There's just too much state
information to restore if the config wizard is run a second time.

Also, removed a bunch of old Registry settings readings (v3.10/11
upgrade support) and commented out code.