run-tests: record ignored tests by raising IgnoreTest

run-tests: record skips by raising SkipTest The unittest way of recording a skipped test is to raise an exception (at least with modern unittest implementation). We change Test to raise a SkipTest when operating in unittest mode. This does prevent some "tear down" activities from running in unittest mode. This will be fixed in subsequent patches. Since unittest mode is experimental, this should be OK.

run-tests: implement TestCase.run() Simply wrapping TestCase.run() is not sufficient for robust results reporting because unittest in Python 2.4 does not know about things like skipped tests and reports them as success or failures instead of skips. We will reimplement TestCase.run() with knowledge and semantics present in modern Python releases.

run-tests: don't print progress from Test when in unittest mode unittest does its own printing of progress indicators as part of TestResult. So, there is no need to print them when running in unittest mode. This will fix the double output of progress indicators that had been occurring in unittest mode.

run-tests: define a custom TestSuite that uses _executetests() We now have a custom unittest.TestSuite implementation that uses _executetests() and thus knows how to execute tests concurrently. Running tests in --unittest mode will use this TestSuite. Since the TestSuite handles concurrency, the warnings around --jobs and --loop have been removed.

run-tests: pass an optional TestResult into _executetests() If the result is passed, we execute tests in the unittest way. A subsequent patch will actually do this.