Create functionality: cancellation of account

[maryann]

(originally reported to Khaled and Maryann by Chris)

Users want to be able to "cancel their accounts"

This could mean various things like:
-No longer receiving e-mails (not the problem, they aren't being sent e-mails)
-disabling the ability for someone to click on the user's screenname and be sent to a profile (removing its link)
-making the profile impossible to access

Some things to consider:
- What if the person wants to re-signup?
- What will happen to the user's created content, most importantly their comments?