Pull changes to collect domain fronting dialing stats

Closes getlantern/lantern#1913  Includes changes that require changes on the Java side, see https://github.com/getlantern/lantern/pull/1921
s/Otherwise/If the MasqueradeSet is not specified/  ?  Probably obvious from context, but this "Otherwise" is closer to the `If the MasqueradeSet is "cloudflare"` than to the `(if specified)`.