fixed resource management for generated images

diff --git a/bundles/org.eclipse.rap.rwt/src/org/eclipse/swt/graphics/GC.java b/bundles/org.eclipse.rap.rwt/src/org/eclipse/swt/graphics/GC.java
index be62a2a..dc377a2 100644
--- a/bundles/org.eclipse.rap.rwt/src/org/eclipse/swt/graphics/GC.java
+++ b/bundles/org.eclipse.rap.rwt/src/org/eclipse/swt/graphics/GC.java

@@ -20,6 +20,7 @@
 import javax.imageio.ImageWriter;
 import javax.imageio.stream.ImageOutputStream;
 
+import org.eclipse.rwt.RWT;
 import org.eclipse.rwt.internal.ConfigurationReader;
 import org.eclipse.rwt.internal.IEngineConfig;
 import org.eclipse.rwt.internal.resources.ResourceManager;
@@ -567,6 +568,11 @@
     } finally {
       writer.dispose();
     }
+    try {
+      RWT.getResourceManager().register( "generated_" + image.hashCode(), new FileInputStream( location ) );
+    } catch( FileNotFoundException e ) {
+      e.printStackTrace();
+    }
   }
 
   private static ImageWriter getImageWriter() {
@@ -584,8 +590,7 @@
   private static File getImageResourceLocation( final Image image ) {
     IEngineConfig engineConfig = ConfigurationReader.getEngineConfig();
     File serverContextDir = engineConfig.getServerContextDir();
-    String filename = "gen_" + image.hashCode();
-    ResourceFactory.images.put( filename, image );
+    String filename = "rwt-resources/resources/generated/image_" + image.hashCode();
     return new File( serverContextDir, filename );
   }
 

diff --git a/bundles/org.eclipse.rap.rwt/src/org/eclipse/swt/graphics/Image.java b/bundles/org.eclipse.rap.rwt/src/org/eclipse/swt/graphics/Image.java
index 51ded8f..d0bcc38 100644
--- a/bundles/org.eclipse.rap.rwt/src/org/eclipse/swt/graphics/Image.java
+++ b/bundles/org.eclipse.rap.rwt/src/org/eclipse/swt/graphics/Image.java

@@ -97,7 +97,7 @@
   public Image( Display display, int x, int y ) {
     this.width = x;
     this.height = y;
-    ResourceFactory.images.put( "resources/generated/image_" + Math.random(), this );
+    ResourceFactory.images.put( "generated_" + this.hashCode(), this );
   }
 
   // RAP [bm]: e4-enabling hacks