title: How to get all product from a category including its subcategories in Magento?
body: <p>I'm looking for a way to retrieve all products from a category includings its subcategories and return me a Product Collection.</p>
  
  <p>I know I can iterate over categories to get ids of product and load them in the view, but I would have liked to get a product collection as it is done currently in most categories/views.</p>
  
  <p>Any ideas?</p>