setters should provide fluent interface

setNew, setDeleted and resetModified should return $this as all the other setters to provide fluent interface.

runtime/lib/om/BaseObject.php

@@ -116,10 +116,12 @@ public function isNew()
      * by Propel-generated children and Peers.
      *
      * @param boolean $b the state of the object.
+     * @return self
      */
     public function setNew($b)
     {
         $this->_new = (boolean) $b;
+        return $this;
     }
 
     /**
@@ -137,11 +139,12 @@ public function isDeleted()
      *
      * @param boolean $b The deleted state of this object.
      *
-     * @return void
+     * @return self
      */
     public function setDeleted($b)
     {
         $this->_deleted = (boolean) $b;
+        return $this;
     }
 
     /**
@@ -242,7 +245,7 @@ public function postHydrate($row, $startcol = 0, $rehydrate = false)
      *
      * @param string $col If supplied, only the specified column is reset.
      *
-     * @return void
+     * @return self
      */
     public function resetModified($col = null)
     {
@@ -253,6 +256,7 @@ public function resetModified($col = null)
         } else {
             $this->modifiedColumns = array();
         }
+        return $this;
     }
 
     /**