tests: Use tap automake testing scripts, fixes output summaries

https://bugzilla.gnome.org/show_bug.cgi?id=734089
libtracker-data: Improve unit tests calling g_test_add()

This includes a setup and teardown function to clean up properly.
This was needed because the new framework seems to run tests in parallel and
was randomly failing because the same data dir was being used for all tests.