[Feature] Native SMS Bridging

As a user, a major convenience add from using Matrix would be native bridging to SMS. If this were the case, by virtue of using Matrix the ability to interact with SMS from any platform (e.g. Laptop, Tablet, etc.) communications opportunities through Matrix would increase vastly as most of the world uses SMS as a baseline level of communications. Through the convenience add of having this communication ability on any platform, and consolidated, the value of Matrix to a layperson would increase dramatically.

The main foreseeable issue with implementing this appears to be puppeting the SMS users in Matrix without the use of a bot account, or access to the homeserver's application services API.

Perhaps there is a way around this, or maybe there needs to be a feature like 1:0 room puppeting in the matrix spec.

Please let me know your thoughts on this issue.