Ttf 034

See merge request !2

+ ttcn3 generation fixes for enums, dataelementuse, and others

See merge request !1

+ debugging operation

OCL Java code generator optimizes away the first condition "not self.container().oclIsUndefined()" because it thinks that "self.container()" can never be null although the return value is marked optional (assuming a bug in Pivot OCL)

(cherry picked from commit 113e8c05)