REORG: include: move port_range.h to haproxy/port_range{,-t}.h

The port ranges didn't depend on anything. However they were missing
some includes such as stdlib and api-t.h which were added.
diff --git a/src/server.c b/src/server.c
index 324dc97..5c26de3 100644
--- a/src/server.c
+++ b/src/server.c
@@ -34,7 +34,7 @@
 #include <proto/cli.h>
 #include <proto/checks.h>
 #include <proto/connection.h>
-#include <proto/port_range.h>
+#include <haproxy/port_range.h>
 #include <haproxy/protocol.h>
 #include <proto/queue.h>
 #include <proto/sample.h>