Use JUnit4's @RunWith and @Suite to simplify test suites.

JUnit4 offers the annotations @RunWith and @Suite, which allow to
group test classes in suites in a simpler and more legible way.
Merge pull request #102 from altenbernd/junit4-suites

Use JUnit4's RunWith and Suite annotations to simplify test suites.
Credits for last merge.
Merge remote-tracking branch 'upstream/master'