add page options to model
create sectionpage template and css
hide subpages from index for sectionpages
recursively calculate latest activity time
check is_sectionpage recursively
create page comments view
hide pro/contral/neutral in comments form for norms
create pager selections view
fix ret_url for proposal create
apply Page.allow_selection option

I was not completely sure about the scope of this task.

If I have gone to far in some places it should be simple
to revert my changes
apply Page.allow_comment option

I was not completely sure about the scope of this task.

If I have gone too far in some places it should be simple
to revert my changes
Allow to render markdown text

I searched for a canonical way to render a text
but there seem to be dozens of ways to do that.