helper class for showing changes properties in a prefab instance, needs a StringListWindow helper that just prints a bunch of strings to an editor window

ListPrefabChanges.cs

using System;
using System.Linq;
using UnityEngine;
using UnityEditor;

public class ListPrefabChanges : EditorWindow
{
    [MenuItem("Tools/List Prefab Changes")]
    private static void Command()
    {
        var propertyMods = from pm in PrefabUtility.GetPropertyModifications(Selection.activeGameObject)
                           where !(pm.propertyPath.StartsWith("m_LocalRotation") || pm.propertyPath.StartsWith("m_LocalPosition"))
                           select pm;
        var propertyStrings = propertyMods.Select<PropertyModification, string>(ConstructPropertyString);
        StringListWindow.ShowStringList("Prefab Changes", propertyStrings);
    }

    private static string ConstructPropertyString(PropertyModification pm)
    {
        var comp = pm.target as Component;
        var gob = pm.target as GameObject;

        if (comp != null) {
            return comp.transform.GetHierarchyPath() + ": " + comp.GetType().Name + "." + pm.propertyPath + "    " + pm.value;
        } else if (gob != null) {
            return gob.transform.GetHierarchyPath() + "." + pm.propertyPath + "    " + pm.value;
        }

        return "Unknown target type: " + pm.target.GetType().Name;
    }
}