All RPATH setting have to be set before generation of any binary.
Defining of CMAKE_INSTALL_RPATH is moved to separate file which is called from main CMakeLists.txt in the beginning, just after install_layout.cmake
The TARBALL variable controls if a special tar.gz package is built when
packages are generated. This package has a different directory structure
compared to the RPM/DEB packages.
If RPM/DEB packages are built, tar.gz packages are not built. This makes
RPM/DEB generation faster and allows tarballs to be built separately with
a proper directory structures.
