Added support s/getImage(uint i) and getNumImages().

src/osg/TextureRectangle.cpp

@@ -182,11 +182,11 @@ void TextureRectangle::apply(State& state) const
 
         textureObject->setAllocated(1,_internalFormat,_textureWidth,_textureHeight,1,0);
 
-        // in theory the following line is redundant, but in practice
-        // have found that the first frame drawn doesn't apply the textures
-        // unless a second bind is called?!!
-        // perhaps it is the first glBind which is not required...
-        //glBindTexture(GL_TEXTURE_RECTANGLE, handle);
+        if (_unrefImageDataAfterApply && areAllTextureObjectsLoaded() && getDataVariance()==STATIC)
+        {
+            TextureRectangle* non_const_this = const_cast<TextureRectangle*>(this);
+            non_const_this->_image = 0;
+        }
     }
     else
     {