the previous and next posts are now supplied in json of the presenter; give the template creator a default value

Go to root page if deleting post from the show page

Conflicts:
	public/javascripts/app/router.js
	public/stylesheets/sass/application.sass

Adjust redirection logic.

add a missing test for block user, and fix ignoring a user from a non stream page; rename a javascript method as it was actually the oppisite of what it said it was doing

This reverts commit 8507dc86.