create instance option display_category_pages
allow long badge descriptions
add category image

Conflicts:
	src/adhocracy/config/routing.py
	src/adhocracy/controllers/category.py
add config ui for category image

Conflicts:
	src/adhocracy/controllers/badge.py
allow to set proposal category in query on new
add parameter extra_filter to solr_proposal_pager
add parameter visible_only to model.badge.all
add category tab to instance navigation
create category views
only show leaves in category index
use pages_pager in category sidebar
fix migration numbering
fix wording

watch -> view
also fix case
fix long_description config template

if instance.display_category_pages was False the template
did not include an input element for long_description.
That way the form was always invalid.
fix category url

If the title contains a dot it will be interpreted as format.
This avoids that by using id instead of title in the url.
Merge pull request #695 from xi/feature-expand-category+

expand category