Adjust to the moving target called the C++ standard. Apparently nowadays it's not allowed to define an explicit copy constructor but not an assignment operator. Consequently, defining the explicit copy constructor in terms of the implicit/automatic assignment operator for general convenience no longer works. Add assignment operators. Caution: not tested with the IBM compiler, but there's no particular reason it shouldn't work.

/* This file is rewritten by release scripts; nothing may be added to it. */
#define INTVERSION        240
#define BASEVERSION       "2.40"
#define BASEVERSIONSTRING "Version 2.40"
#define VERSION           "2.40-current"
#define VERSIONSTRING     "Version 2.40-current"