Use Unicode for varchar.
Improve the dump() method to escape HTML.
Save the object in the scope instead of the rendering. This allow to
show some informations about a node for each inclusion.
Methods injected in the scope are now prefixed by a '_' in order to
not conflict with variables.
Write less.
Add a 'ref' attribute for Nodes which allow a custom
string to reference an existing Node.
Add a method to augment the scope of the current node
with the scope of an another node referenced by ref.