Make cppunittest work

[dmik]

The cppunittest test suite works per se (starts via mach cppunittest) but there are some tests that fail, a quote from #247 (comment):

Note that besides TestStartupCache.exe (e.g. if I Ctrl-Break it and let the suite continue) there are >4 other failed CPP unit tests (with 76 succeeded):

TEST-UNEXPECTED-FAIL | TestFile.exe | test failed with return code 1
TEST-UNEXPECTED-FAIL | TestTXMgr.exe | test failed with return code -5
TEST-UNEXPECTED-FAIL | test_audio.exe | test failed with return code -6
TEST-UNEXPECTED-FAIL | test_sanity.exe | test failed with return code -6