ZF-8007: using own namespace for resource plugins


The examples under section 4.4 shows using the namespace "My_", if the developer tries the example, it would result to error "class not found". The manual should note that the namespace "My_" should also be registered, or the initialization of Zend_Application should also pass the option for registering additional namespace.


Notes added to manual in trunk and 1.10 release branch.