release/21.2.18.0

James Catmore

@jcatmore

a9c8108d · Merge branch 'macOSFixes-21.2-20180308' into '21.2' · Mar 08, 2018

AthDerivation-21.2.18.0, largely the same as 21.2.17.0 but fixes two crashes in EXOT8 and FTAG1.