Fix Issue #243 and Issue #244:
 - add_flow.py ignores src/dst mac address matching (#243)
 - add_flow.py ignores matchSrcIPv4Net and matchDstIPv4Net (#244)

The root cause for both issues was incorrect Python identation
of a return statement: it was in the wrong level, hence the
arguments parsing was incorrect.
The issue was introduced in the last change to add_flow.py:
commit 08eb7325e726b621dd35be113e365eaefdbd81b9
diff --git a/web/add_flow.py b/web/add_flow.py
index 28819c9..9b5ab42 100755
--- a/web/add_flow.py
+++ b/web/add_flow.py
@@ -276,18 +276,18 @@
       log_error(usage_msg)
       exit(1)
 
-    return {
-      'my_flow_id' : my_flow_id,
-      'my_installer_id' : my_installer_id,
-      'my_src_dpid' : my_src_dpid,
-      'my_src_port' : my_src_port,
-      'my_dst_dpid' : my_dst_dpid,
-      'my_dst_port' : my_dst_port,
-      'match' : match,
-      'matchInPortEnabled' : matchInPortEnabled,
-      'actions' : actions,
-      'actionOutputEnabled' : actionOutputEnabled
-      }
+  return {
+    'my_flow_id' : my_flow_id,
+    'my_installer_id' : my_installer_id,
+    'my_src_dpid' : my_src_dpid,
+    'my_src_port' : my_src_port,
+    'my_dst_dpid' : my_dst_dpid,
+    'my_dst_port' : my_dst_port,
+    'match' : match,
+    'matchInPortEnabled' : matchInPortEnabled,
+    'actions' : actions,
+    'actionOutputEnabled' : actionOutputEnabled
+    }
 
 def compute_data_path(parsed_args):