decorate tempfile name's to help identify leaks' author

unottols TempFile class check in debug bod for
and env variable LO_TESTNAME.. if present it use that as the root
for the tempfile filename.

cppunitteset framework is augmented so that it export such
LO_TESNAME using the cppunit testName(), after replacement of
non-alphnum characters by _

Change-Id: Iebb9545d3bd789083afbeaf4c64eab086b56049a