java_gen: create DEFAULT instance for objects that support it (for Match)

Objects which consist only of parts that have a default value
now get a default value.

Match, in particular, now defines a default instance that wildcards
everything and is available as factory.matchWildcardAll()
diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFPort.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFPort.java
index cb36d0c..0028cd8 100644
--- a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFPort.java
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFPort.java
@@ -87,12 +87,17 @@
      * output port). NOTE: OpenFlow 1.0 calls this 'NONE'
      */
     public final static OFPort ANY = new NamedPort(OFPP_ANY_INT, "any");
+    /** the wildcarded default for OpenFlow 1.0 (value: 0). Elsewhere in OpenFlow
+     *  we need "ANY" as the default
+     */
+    public static final OFPort ZERO = OFPort.of(0);
 
     public static final OFPort NO_MASK = OFPort.of(0xFFFFFFFF);
-    public static final OFPort FULL_MASK = OFPort.of(0x0);
+    public static final OFPort FULL_MASK = ZERO;
 
     /** cache of frequently used ports */
     private static class PrecachedPort {
+        private final static OFPort p0 = new OFPort(0);
         private final static OFPort p1 = new OFPort(1);
         private final static OFPort p2 = new OFPort(2);
         private final static OFPort p3 = new OFPort(3);
@@ -160,6 +165,8 @@
      */
     public static OFPort ofInt(final int portNumber) {
         switch (portNumber) {
+            case 0:
+                return PrecachedPort.p0;
             case 1:
                 return PrecachedPort.p1;
             case 2:
@@ -302,6 +309,8 @@
      */
     public static OFPort ofShort(final short portNumber) {
         switch (portNumber) {
+            case 0:
+                return PrecachedPort.p0;
             case 1:
                 return PrecachedPort.p1;
             case 2: