[tests] Don't import QUnitTestCase into tests' global namespace Unittest's test loader will try to execute QUnitTestCase's test_javascripts method. However this class is intended to be subclassed, not to be executed directly. This change has the following consequences: * slightly faster test execution * almost all rtags warnings are gone

from os.path import join
assert __file__.endswith(join('scripts', 'script2.py')), __file__
assert '__main__' == __name__, __name__
assert ['-v'] == __args__, __args__