run-tests: capture execution results in a TestResult class
Some implementation details of test execution still live outside of
Test. These include determining what a result means and cleaning up
after the test.
To move to the world where more of this logic can live inside Test or a
derived object, the logic for test execution needs to be refactored.
Specifically, exception trapping and opportunities for result processing
need to be moved into Test.
This patch starts the process by establishing a TestResult class for
holding the results of a test execution. In order to actually use this
class, exception trapping and execution time recording needed to be
moved into Test.run().
run-tests: clean up temp directory variables
testtmp is an implementation detail. It didn't need to be exposed to the
world.
threadtmp is derived from count. It is now created as part of the
constructor and mostly hidden from the outside world.