A few more prerequisite dependency issues solved after the cross-compilation changes
adapt/os/ocpios/linux/driver/Makefile: update to use cross-compile-friendly target variables
generic_env_post.sh: don't share omniorb includes and idls across platforms (for now)
install_omniorb.sh: ditto, and update to 4.1.6
install_gtest.sh: have build directories persist when new targets are built