added javadoc headers

querydsl-core/src/main/java/com/mysema/query/types/ExprException.java

@@ -1,3 +1,8 @@
+/*
+ * Copyright (c) 2010 Mysema Ltd.
+ * All rights reserved.
+ * 
+ */
 package com.mysema.query.types;
 
 public class ExprException extends RuntimeException{

querydsl-core/src/main/java/com/mysema/query/types/PathMetadata.java

@@ -26,7 +26,6 @@ public final class PathMetadata<T> implements Serializable{
     
     private static final long serialVersionUID = -1055994185028970065L;
 
-    // Expr is in lower level package
     private final Expr<T> expression;
 
     private final int hashCode;