ctest-remove-declarative-script-mode

• CTest's declarative scripting mode has been removed. This mode used to be triggered by a ctest -S script which did not call any CTest Commands unless CTEST_RUN_CURRENT_SCRIPT was explicitly set to OFF. This feature was undocumented and was not covered by any unit tests.

• The CTEST_RUN_CURRENT_SCRIPT variable no longer has any special meaning.

• The ctest_run_script() command may no longer be called without any arguments.