Fix spelling, update links.

deformdemo/__init__.py

@@ -479,7 +479,9 @@ def popup(self):
        .. note ::

            Pop up form templates are NOT supplied with Deform core.
            They are in ddemonstrationckage for demostration purposes.
            They are in the deformdemo package for demostration purposes.
            You can copy them to your own project and configure
            widget template paths.

        popup_example.pt contains the page HTML template.

@@ -489,6 +491,12 @@ def popup(self):
        Template registration: See ``deformdemo.main`` how we register a template path
        ``custom_widgets`` where the custom form template lies.
        See also :ref:`templates` in Deform documentation for more information.

        Source code:

        https://github.com/Pylons/deformdemo/blob/master/deformdemo/templates/popup_example.pt

        https://github.com/Pylons/deformdemo/blob/master/deformdemo/custom_widgets/modal.pt
        """

        class Schema(colander.Schema):