New ctest regression test suite to replace nosetests

Just wanted to get this PR started. With the new cmake build system in place, I converted nosetests to ctests.  Now after building the code with make you can now run ```make test``` to test your build. The run_tests.py script has also been modified to support this new testing system.

Tasks left
- [ ] Update documentation
- [ ] Add some command line options to support some ctest command line options (i.e., -R)
- [ ] Be able to run tests in parallel