[TESTS] add a test case for port mapping

tests/test-map-ports.cfg

@@ -0,0 +1,31 @@
+# This is a test configuration.
+# It presents 4 instances using fixed and relative port assignments from
+# ports 8001 to 8004. TCP only is used, and the destination address is not
+# relevant (use netstat -an).
+
+global
+	maxconn		100
+
+defaults
+        mode            tcp
+        clitimeout      15000
+        srvtimeout      15000
+        contimeout      15000
+	balance roundrobin
+
+listen  fixed
+        bind		:8001
+	server s1 1.1.1.1:8001
+
+listen  same
+        bind		:8002
+	server s2 1.1.1.2
+
+listen  plus1000
+        bind		:8003
+	server s3 1.1.1.3:+1000
+
+listen  minus1000
+        bind		:8004
+	server s4 1.1.1.4:-1000
+