Ensure that only the relative grammar path is encoded in the generated java paths

Regenerating the java files from the grammar is now reproducible.
diff --git a/java/languages.antlr/build.xml b/java/languages.antlr/build.xml
index 8c713f4..e2ed557 100644
--- a/java/languages.antlr/build.xml
+++ b/java/languages.antlr/build.xml
@@ -44,13 +44,13 @@
             <fileset dir="../../ide/libs.antlr3.runtime/external" includes="antlr-runtime-*.jar"/>
         </path>
 
-        <java classname="org.antlr.v4.Tool" classpathref="antlr4.tool">
+        <java classname="org.antlr.v4.Tool" classpathref="antlr4.tool" fork="true" dir="${antlr.outdir}">
             <arg value="-o"/>
             <arg value="${antlr.outdir}"/>
-            <!--arg value="-package"/><arg value="org.antlr.parser.antlr4"/-->
-            <!--arg value="-visitor"/-->
-            <arg value="${antlr.outdir}/ANTLRv4Lexer.g4"/>
-            <arg value="${antlr.outdir}/ANTLRv4Parser.g4"/>
+            <arg value="-package"/>
+            <arg value="org.antlr.parser.antlr4"/>
+            <arg value="ANTLRv4Lexer.g4"/>
+            <arg value="ANTLRv4Parser.g4"/>
         </java>
 
         <delete dir="${antlr.outdir}" includes="*.tokens"/>
diff --git a/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Lexer.java b/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Lexer.java
index e0b6e0e..e91592a 100644
--- a/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Lexer.java
+++ b/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Lexer.java
@@ -1,4 +1,5 @@
-// Generated from /home/lkishalmi/NetBeansProjects/netbeans/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Lexer.g4 by ANTLR 4.7.2
+// Generated from ANTLRv4Lexer.g4 by ANTLR 4.7.2
+package org.antlr.parser.antlr4;
 
 /*
  * Licensed to the Apache Software Foundation (ASF) under one
diff --git a/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Parser.java b/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Parser.java
index 7df66de..7edf184 100644
--- a/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Parser.java
+++ b/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Parser.java
@@ -1,4 +1,5 @@
-// Generated from /home/lkishalmi/NetBeansProjects/netbeans/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Parser.g4 by ANTLR 4.7.2
+// Generated from ANTLRv4Parser.g4 by ANTLR 4.7.2
+package org.antlr.parser.antlr4;
 
 /*
  * Licensed to the Apache Software Foundation (ASF) under one
diff --git a/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4ParserBaseListener.java b/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4ParserBaseListener.java
index a13ce6a..2030201 100644
--- a/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4ParserBaseListener.java
+++ b/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4ParserBaseListener.java
@@ -1,4 +1,5 @@
-// Generated from /home/lkishalmi/NetBeansProjects/netbeans/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Parser.g4 by ANTLR 4.7.2
+// Generated from ANTLRv4Parser.g4 by ANTLR 4.7.2
+package org.antlr.parser.antlr4;
 
 /*
  * Licensed to the Apache Software Foundation (ASF) under one
diff --git a/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4ParserListener.java b/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4ParserListener.java
index 0366015..4748de3 100644
--- a/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4ParserListener.java
+++ b/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4ParserListener.java
@@ -1,4 +1,5 @@
-// Generated from /home/lkishalmi/NetBeansProjects/netbeans/java/languages.antlr/src/org/antlr/parser/antlr4/ANTLRv4Parser.g4 by ANTLR 4.7.2
+// Generated from ANTLRv4Parser.g4 by ANTLR 4.7.2
+package org.antlr.parser.antlr4;
 
 /*
  * Licensed to the Apache Software Foundation (ASF) under one