Fix snprintf test and output result to TAP format

Replace the tap library with the one used by babeltrace's test suite which
offers more functionality and outputs in a truly TAP-compliant format.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Clean-up of configure.ac and tests/Makefile.am

Removal of disabled tests. Fixes ./configure failing
in distribution package because by missing Makefiles
in tests/ust-basic-tracing and tests/ust-multi-test.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Convert hello.cxx test to a build test

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Remove tests depending on consumerd