Drop the option to test with a different generator and make program than
was used to build.  This was used only to test support for the Open
Watcom compiler which at one time could not build CMake.  Instead we
will allow CMake to be configured to skip building binaries and just run
the test suite using an external CMake (in a future change).

For now leave the two option variables hard-coded to the old option
defaults until code can be updated to stop using them.