Adrien Béraud authored Apr 18, 2017 and Guillaume Roguez committed May 04, 2017

Add Argon2 as an independent package instead of building the version
shipped with OpenDHT, to better track Argon2 version,
and allow using the system version if available (and profit from
security updates).

Bump OpenDHT to release 1.3.1 from intermediate commit, bringing
minor bug fixes and performance improvements.

Change-Id: I2c697a95ca77b8de5241c329016a2aa349f4453b