Cfblog

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* removed redundant html parsing. this will decrease the cms rendering time significantly.
* removed mutable defaults for JSONField.

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* support for mutiple static page categories

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* fix for migrations failing if `cfblog` is migrated before `sites` app
* publish button now checks for publish permissions using settings rather than user permissions

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* If `DEBUG` is enabled `render_to_response` do not wrap exceptions as `Http404`

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* `parse_cms_template` takes `template_context` which will be used to render the included snippets
* renamed the argument `dictionary` to `cms_context` in `parse_cms_template` [Backward Incompatible]
* added two settings `CFBLOG_CAN_EDIT` and `CFBLOG_CAN_PUBLISH` which should take the user and return if the user has permission to edit or publish the content respectively

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* added support for new attribute `data-cms-replace`. when used in conjuction with `data-cms-content` will replace the tag instead of inserting into it
* renamed the argument `publish` to `public` in `parse_cms_template` [Backward Incompatible]
* `render_to_response` takes a new param `public` which will be passed to `parse_cms_template`
* added a model method `get_public_html` for `Content` to get the public html without publishing [might raise exceptions]
* can filter `Contet` using author in admin UI
* bug-fixes