def edit
      @post = Post.includes(:user, :discussion).find(params[:id])
      raise Cornerstone::AccessDenied unless @post.created_by?(current_cornerstone_user)
      @discussion = @post.discussion
      respond_with(@discussion, @post)
    end
def edit
      @post = Post.includes(:user, :discussion).find(params[:id])
      raise Cornerstone::AccessDenied unless @post.created_by?(current_cornerstone_user)
      @discussion = @post.discussion
      respond_with(@discussion, @post)
    end
GET /cornerstone/discussions/:discussion_id/posts/:id/edit