Fix SMBG disambiguation bugs
Fix SMBG disambiguation bugs

The last change to findMatchingClosedLoopBGReadings introduced a bug
that caused no matching events to be found. Fixed that bug.
Discovered that it's also possible for manually entered events to have
matching BG_SI results. Handle that now, so that extra events are not
sent to Tidepool.
- Bug fix for https://trello.com/c/jnkv0yVy

tidepool-org/chrome-uploader,tidepool-org/chrome-uploader,tidepool-org/chrome-uploader