[cmake] Give error if installing to /usr, /usr/local/
[cmake] Give error if installing to /usr, /usr/local/

opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core