track replies should require forward reply email address

When you select Track reply in a civi mailing, the text reads: "Recipients' replies are sent to a CiviMail specific address instead of the sender's address so they can be stored within CiviCRM." This implies that the entire reply is stored in CiviCRM, when in fact it seems that just the timestamp of the reply is stored in CiviCRM.

Additionally, users have the option of specifying an email address that replies get forwarded to.

I think it would be an improvement if we made the following changes:

• When you check track replies, require a forwarding email address. I can't think of a common use-case when someone wants replies sent to CiviCRM but doesn't ever want to read those replies.
• Change the language to read: Recipients' replies are sent to a CiviMail specific address instead of the sender's address so statistics can be collected on the number of replies. NOTE: the content of the reply is not stored in CiviCRM."