Added a C++ and a GLSL implementation of a 64-bit CRC algorithm.

Changed hardcoded checksum value in ooxmlimport unit test (testN777345).

Change-Id: I16bb985a14866775efda49e21fe033ff64645896
Reviewed-on: https://gerrit.libreoffice.org/18254Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>