SEMS modules

The easiest way to take advantage of the sems modules is to load them via source Trilinos/cmake/load_sems_dev_env.sh which will work well for both RHEL 6 and 7. It will automatically provide you a set of compilers and associated TPLs that allow you to compile Trilinos out-of-the-box. Additionally it allows you to use the checkin-test-sems.py script that ensures what you push to github has a chance not to break builds for others.