autotest: use sub-string matching for test selection

typing the full names is rather tedious when they get long.
also, using sub-strings, we can match multiple tests with one argument.

src/run-tests.pl

@@ -789,7 +789,7 @@ sub test($$$$)
 {
 	my ($ttl, $sx, $tx, $sfx) = @_;
 
-	return 0 if (scalar(@ARGV) && !grep { $_ eq $ttl } @ARGV);
+	return 0 if (scalar(@ARGV) && !grep { index($ttl, $_) >= 0 } @ARGV);
 	print "Testing: ".$ttl." ...\n";
 	writecfg($sfx);