Stop tests after failures

Call mtc.stop after setverdict(fail), add reasons to most failures and
fail with verdict error for internal errors.

Change-Id: I9b618235939fa41160b9be6677b121963d3ec857
diff --git a/selftest/Selftest.ttcn b/selftest/Selftest.ttcn
index 826d244..8411b3d 100644
--- a/selftest/Selftest.ttcn
+++ b/selftest/Selftest.ttcn
@@ -57,7 +57,7 @@
 	res := IPL4asp_PortType.f_IPL4_connect(IP, "127.0.0.1", 55555, "", -1,-1, {tcp:={}});
 	if (not ispresent(res.connId)) {
 		setverdict(fail, "Could not connect to TCP port, check your configuration");
-		self.stop;
+		mtc.stop;
 	}
 	g_ip_conn_id := res.connId;
 }