Set "notify me when a reply is posted" to yes by default

[janschreier]

I would suggest putting this setting to yes by default. ATM is "no". I think this results in some comments initially being answered and once there is an additional questions this gets overlooked, which is frustrating for the person who asked and also for anybody who used the search engine (and I used it a lot in the last days ;)

One can still tick it off every time one doesn't want to receive mails (maybe you can add this as a comment behind the option: "You can change this default setting in your profile")