Add Breadcrumbs

[sveetch]

There is currently no breadcrumbs, i could make it almost hardcoded in templates using a block and block.super, but it may not be the best way.

However i'm not sure this is the most urgent thing to develop a little module to manage breadcrumbs from code (likerly used in a templatetag).

[sveetch]

The zinnia way to do it from code seems nice:

https://github.com/emencia/django-blog-xinnia/blob/master/zinnia/breadcrumbs.py

i didn't looked deep on the code and there are some things i won't do the same way but it may be a good approach.

[sveetch]

This package may be a nice implementation https://github.com/tj-django/django-view-breadcrumbs i need to dig a little more to see how it works.

[sveetch]

Done with django-view-breadcrumbs as an optional feature (enabled only if extra requirement 'breadcrumb' has been installed).