Instead of a copy of a message by email, allow messages from the inbox
to be sent via SMS, and allow the user to choose how they receive
messages, either by email, SMS, neither or both.

Details:
1) Add one site settings, SMS gateway. The SMS gateway is used in conjunction with the user's cell phone number from the profile to send them a message via SMS.

2) Add Two User Profile settings, Send Inbox Messages via Email (Yes/No) and Send Inbox Messages via SMS (Yes/No).

This feature be used in conjunction with this RFE to have new inbox message notifications sent out to users via SMS.