* support setting duplication in filetype configuration
    function = {
      template = "my template";
      # more settings...
    }
    prototype = function;
    macro     = function;
  This would be really convenient with function, macro and prototypes for
  example.

* Support doctype-specific user-defined environment chunks.
  Problem: there is (for now) nothing here for this kind of settings
  (doctype-global but also specific to it).

* Store doctype in a per-document basis? It would be cool, but not sure it is
  possible without re-implementing a lot of document history.

* Support multiple cursors in templates
