Cleanup and rearrangements in Match structure and fields.
1. Added full documentation for the Match interface
2. Added Builder into Match interface and removed the separate class
3. Added ability to declare field prerequisites in the MatchField class and then check that they are
met using a given Match object
4. Fixed some small issues in value types and added a value type for Metadata
diff --git a/java_gen/pre-written/src/main/java/org/openflow/protocol/match/MatchFields.java b/java_gen/pre-written/src/main/java/org/openflow/protocol/match/MatchFields.java
index 21043f2..309f91f 100644
--- a/java_gen/pre-written/src/main/java/org/openflow/protocol/match/MatchFields.java
+++ b/java_gen/pre-written/src/main/java/org/openflow/protocol/match/MatchFields.java
@@ -1,5 +1,6 @@
package org.openflow.protocol.match;
+// MUST BE ORDERED BY THE ORDER OF OF SPEC!!!
public enum MatchFields {
IN_PORT,
PHYSICAL_PORT,