swift 2.10.0 was released in 2016. We no longer need to support even
older versions. The output format depends on the version currently
installed, thus the latest logic should work as long as the same
release (or even a bit older release) is installed.
This also updates the logic to skip the header lines. The new logic
is considered to be more robust, because it works even when additional
lines are added.
Change-Id: I694ca4c046f490e4ffecf2101f3f147a69045162
8ac0db4928