update to MAPref v2.2
Updated reference to MAPref v2.2:
- fixed multithreaded race condition affecting occurring on some machines
- v2.0 had an over-proportional increase in number of OTUs compared to v1.0 due to changes introduced in the alignment and trim settings. This has now been rectified and the increase is more inline with expectations.
- Several sequences in v1.0 were missing in v2.0 and are now included in the new version.