Add new render_menu_below template tag
Refactor based on discussion in #21
More refactoring. You can now specify a path, id or page object
Missed try/except block
Merge pull request #21 from borgstrom/selective-menus

Add new render_menu_below template tag
Update AUTHORS file and changelog with recent contributions
Minor assorted improvements to the recent pull

- PEP8 spacing
- read dictionary value once
- isinstance() checks for UrlNode includes Page
- isinstance() check for (int, long) to deal with Django PK values.
- Using TemplateSyntaxError to report errors

Many thanks to Evan Borgstrom for the original work!
Show menu children instead of the parent when given a 'parent' keyword.

After all, the keyword `parent` suggests that the menu items have the
given object as parent.

CC: Pull #21
Fix missing in_navigation() call for `render_menu parent=page`