send oppName in result

Not suggesting you merge this, I'm sure there is a ton wrong with it, I barely know C++ anymore. 

I'd like to be able to log the opponent's name, and see their name in the game display on the website.

I can't speak to what happens after the JSON hits your server, but up to that point this does seem to work.

The matching regex is terrible, should be better, and gamertag's can probably have other characters in them. 

I have two reasons for wanting to log opponent's name:
* Helpful to find people you played previously, etc
* Could enable use of Track-o-Bot as an automatic reporting tool for tournaments.