Converting the test-clone test to test-harness.
Converting test-compositing-order to test-harness.
Converting test-document-timeline to test-harness.
Converting test-duration to test-harness.
Converting test-modify-timing-params to test-harness.
Merge branch 'test-media-fix' into test-conversion
Merge remote-tracking branch 'up/master' into test-conversion
Reverting s/document.timeline/dt/ change.
Merge pull request #197 from mithro/test-conversion

5 more tests converted.