backport IJetDecorator to 21.2
the IJetDecorator is also useful in r21.2. only one change is necessary w.r.t. the version aiming for r22: the return types need to be int to conform to the r21.2 IJetModifier interface.
Edited by Chris Pollard
the IJetDecorator is also useful in r21.2. only one change is necessary w.r.t. the version aiming for r22: the return types need to be int to conform to the r21.2 IJetModifier interface.