Fix the tclsqlite.c TCL interface module so that it works with both Tcl8 and

Fix the tclsqlite.c TCL interface module so that it works with both Tcl8 and
Tcl9.  Make changes across the TCL-based test harness to enable SQLite to
be tested with either Tcl8 or Tcl9.  Get the --with-tcl= argument on the
configure script working. Testing changes only - no changes to the SQLite core.
I believe the previous merge attempt didn't work because of errors in the
merge itself, not because of faults in the code.  Trying again...

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