QVT14 — QVTo : Confusing isVirtual definition for imperative operation calls

The ImperativeCallExp::isVirtual attribute is defined as follows: "Unless isVirtual is true, this invocation is virtual." This is extremely counter-intuitive and apparently stems from a careless renaming. As a result, virtual call semantics are disabled by default, because the default value 'true' implies that an operation is "statically called". The default should be virtual call semantics, so the description should be turned around.