CppTools: Cleanup header/source test

Dynamically create data files in tempPath and clean them up when
finished.

Change-Id: Ie78f557b185b264acc0d0f5814646c203d8a93f4
Reviewed-by: Petar Perisin <petar.perisin@gmail.com>
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>