Jakub Adam authored Jun 29, 2016 and Olivier Crête committed Oct 26, 2016

Connectivity checks that are fully conforming to [MS-ICE2] should
contain IMPLEMENTATION-VERSION attribute ([MS-ICE2] 2.2.2.2) equal to 2
and their FINGERPRINT should be calculated as described in RFC5389
section 15.5 (i.e. using standard CRC lookup table).

We need this because some Skype for Business clients no longer accept
messages whose FINGERPRINT contains a value calculated using Microsoft's
old custom CRC table (specified verbatim in [MS-ICE2] 3.1.4.8.2).

The change creates a compatibility breakage with legacy Lync clients
which will be fixed in following commits.

Differential Revision: https://phabricator.freedesktop.org/D1136