buildroot

supervisor: security bump to version 3.1.4

Fixes CVE-2017-11610 - The XML-RPC server in supervisor before 3.0.1, 3.1.x
before 3.1.4, 3.2.x before 3.2.4, and 3.3.x before 3.3.3 allows remote
authenticated users to execute arbitrary commands via a crafted XML-RPC
request, related to nested supervisord namespace lookups.

For more details, see
https://github.com/Supervisor/supervisor/issues/964

While we're at it, add hashes for the license files.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>