Cmsplugin-blog-categories

- Added get_translation method to the Category model
- Make admin more robust when objects don't have translations for the current
language.

- Added better way to extend the EntryAdmin

- render_category_links tag now accepts exclude_empty parameter
- you can display the number of posts in a category in the template by using
category.num_posts

- Fixed wrong URL inclusion of original cmsplugin-blog URLs

- Only show entries available in the current language on category list view
(similar to the blog's original entry archive index view)

Initial commit