Merge branch 'master' of git://github.com/melinath/philo

Merge branch 'master' of git://github.com/melinath/philo

* 'master' of git://github.com/melinath/philo:
  Minor bugfix: moved ConstantEmbedNode DoesNotExist reraising so that it actually reraises the DoesNotExist exception.
  Removed referential integrity code. Moved embed templatetag into core. Differentiated ConstantEmbedNode (context-independent) and EmbedNode, analogous to django's ConstantIncludeNode/IncludeNode.
  Added embeddable_content_types registry to track what content types are embeddable. Added tracking of whether a model class run through post_delete has EmbedField instances on it. These save time and trouble in the post_delete cascade.
  Added kwarg capability to embed tag. Adjusted reference substitution to account for kwargs.
  Adjusted to match the new master TemplateField changes. Switched the setting of _embedded_instances to the EmbedField clean method so that validationerrors can be raised. Added South introspection rules. Switched NewsletterArticle to use EmbedFields. Set EmbedNode to pre-calculate templates and instances if appropriate and to suppress any errors that might occur. Made invalid content type references raise a TemplateSyntaxError, in line with the container template tag.
  Added post-save and post-delete signals to manage Embed instances. Added the delete method on the Embed model to remove itself from fields where it is embedded.
  Added methods and functions to support syncing embedded models in post-save.
  Initial embed commit. Implements TemplateField and EmbedField - model fields that validate their contents as templates and templates with embedded content, respectively. Implements the {% embed %} template tag, which allows arbitrary instances to be rendered with a given template. Initial sketch of the embed tracker (which should handle cascading deletions) also in place.
  Switched nodelist crawl to return the more generic 'results' of the crawl, rather than 'nodes'. Fixed missing import for TemplateValidationParser.
  Abstracted the Template container fetcher to a nodelist_crawler which takes a callback to determine if a node should be returned. Put all code related to the crawler into philo.utils.
  Moved a few more miscellaneous things into master from embed that did not belong there, mostly deletions of old code regarding template validation.
  Removed 'dynamic' from the Contentlet model. Added TemplateField to Template model and Contentlet model. Fixed some minor typos and added some comments to the code. Increased verbosity of 'disallowed tag' errors.
  Added template field to master branch. Added monkeypatch for telling if a node includes a template and what that template is - eases container fetching. Added template validator which can allow/disallow tags by using a custom parser. Requires testing.
  Tweaked nodeview error reraising to preserve traceback information.