CTest 2.6.4 crashes if a dashboard script invokes "message()" after
"ctest_test()" or anything else that creates an inner cmCTest object.
The CMake.Install test drives installation using --build-and-test with
the outer CTest driving CMake tests.  We add --force-new-ctest-process
to avoid creation of a cmCTest object inside the outer CTest just in
case it is 2.6.4.