deprecate antlr2 java2groovy classes

if we replace, antlr4 version would be in a different package of a new optional module
diff --git a/src/main/java/org/codehaus/groovy/antlr/java/Groovifier.java b/src/main/java/org/codehaus/groovy/antlr/java/Groovifier.java
index cc551fb..162c844 100644
--- a/src/main/java/org/codehaus/groovy/antlr/java/Groovifier.java
+++ b/src/main/java/org/codehaus/groovy/antlr/java/Groovifier.java
@@ -22,6 +22,7 @@
 import org.codehaus.groovy.antlr.parser.GroovyTokenTypes;
 import org.codehaus.groovy.antlr.treewalker.VisitorAdapter;
 
+@Deprecated
 public class Groovifier extends VisitorAdapter implements GroovyTokenTypes {
     private String currentClassName = "";
     private final boolean cleanRedundantPublic;
diff --git a/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyConverter.java b/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyConverter.java
index 85d4a60..c8c83e3 100644
--- a/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyConverter.java
+++ b/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyConverter.java
@@ -22,6 +22,7 @@
 import org.codehaus.groovy.antlr.parser.GroovyTokenTypes;
 import org.codehaus.groovy.antlr.treewalker.VisitorAdapter;
 
+@Deprecated
 public class Java2GroovyConverter extends VisitorAdapter{
     private final int[] typeMapping;
 
diff --git a/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyMain.java b/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyMain.java
index 3cd02a7..96a6bd0 100644
--- a/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyMain.java
+++ b/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyMain.java
@@ -20,6 +20,7 @@
 
 import java.util.Arrays;
 
+@Deprecated
 public class Java2GroovyMain {
 
     public static void main(String[] args) {
diff --git a/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyProcessor.java b/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyProcessor.java
index d6b47dd..689df7e 100644
--- a/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyProcessor.java
+++ b/src/main/java/org/codehaus/groovy/antlr/java/Java2GroovyProcessor.java
@@ -41,6 +41,7 @@
 import java.util.Iterator;
 import java.util.List;
 
+@Deprecated
 public class Java2GroovyProcessor {
 
     public static void processFiles(List<String> fileNames) throws Exception {
diff --git a/src/main/java/org/codehaus/groovy/antlr/java/PreJava2GroovyConverter.java b/src/main/java/org/codehaus/groovy/antlr/java/PreJava2GroovyConverter.java
index 6c5c1e2..55467c1 100644
--- a/src/main/java/org/codehaus/groovy/antlr/java/PreJava2GroovyConverter.java
+++ b/src/main/java/org/codehaus/groovy/antlr/java/PreJava2GroovyConverter.java
@@ -24,6 +24,7 @@
 import java.util.Stack;
 
 /** This class mutates the Java AST, whilst it is still a Java AST, in readiness for conversion to Groovy, yippee-ky-a ! */
+@Deprecated
 public class PreJava2GroovyConverter extends VisitorAdapter{
     private final Stack stack;