Cppcheck-2.1

This is a minor release.

We have tweaked build scripts.
* When you use USE_Z3=yes, we will handle new versions of z3 better. If you have an old z3 library and get compilation problems you will need to add a z3_version.h in externals.
* The cmake scripts was updated.

There was a couple of bug fixes.

New check:
* for "expression % 1" the result is always 0.