Allows the tests to know the relative clock that will appear in the PRV trace (with one rank only).
Adds ovni_version_check() to test the version at runtime, set the SONAME to the major version and install a symlinks to the complete version: libovni.so -> libovni.so.1 libovni.so.1 -> libovni.so.1.0.0 libovni.so.1.0.0