use UnitTest++ for testing

[smidl]

Testing is a bit ad-hoc now.

Many libraries for unit testing are available. With different level of complexity. See survey on: http://www.opensourcetesting.org/unit_c.php

I have seen (cpptest, cxxtest, and UnitTest?++) the latter looks the most promising. Perhaps it should be copied to /tests and extensively used.

[vbarta]

UnitTest?++ copied into library/tests/unittest-cpp, example of use in library/tests/test_user_info.cpp . Please use UnitTest?++ when adding more tests.

[vbarta]

Upon reflection, performance tests probably shouldn't be included in testsuite (because by definition, they take non-trivial resources, and if testsuite is to be run often, it should run fast), and so it doesn't really matter whether they use UnitTest??++ or not.