Created Unassigned: FilteredStream.AddTrack "OR" operator issue [2616]

I realize that the docs say to add each keyword separately, like so:
```
stream.AddTrack("linvi");
stream.AddTrack("tweetinvi");
```
However, I'd like to add them in one call:
```
stream.AddTrack("linvi,tweetinvi");
```

They both seem to work, with matching tweets received on the stream, and they both produce the same HTTPS request to Twitter (as seen in Fiddler):
```
https://stream.twitter.com/1.1/statuses/filter.json?track=linvi%2Ctweetinvi&stall_warnings=true
```

However, the latter (single-call), comma separated keyword track does not behave as expected. As stated, matching tweets are received on the stream; however, the ```MatchedTweetReceivedEventArgs.MatchingTracks``` is empty.

Further, I found that an associated Action<string> is _not_ called for the latter (single-call), comma separated keyword track.
```
stream.AddTrack("linvi,tweetinvi", tweetMessage => Console.Writeline("This will never be written! :[ "));
```