Test cases: Permanent post link

Please develop test cases for the story "Links at posts" (http://jtalks.org/display/jcommune/backlog)

Test case should cover normal and abnormal flows. Please ensure the behavoir is correct if the post (or entire topic has been removed) has been removed and so on.

Test plan page: http://jtalks.org/display/PM/Test+plan
Test case template: http://jtalks.org/display/PM/Test+Case+Template