move prob core unit tests to their own plugin

de.prob.core.tests/.classpath

de.prob.core.tests/.project

de.prob.core.tests/.settings/org.eclipse.jdt.core.prefs

de.prob.core.tests/META-INF/MANIFEST.MF

de.prob.core.tests/build.properties

...mainobjects/ltl/unittests/CounterExampleAllUnitTests.java

...omainobjects/ltl/unittests/CounterExampleAndUnitTest.java

...nobjects/ltl/unittests/CounterExampleFinallyUnitTest.java

...objects/ltl/unittests/CounterExampleGloballyUnitTest.java

...nobjects/ltl/unittests/CounterExampleHistoryUnitTest.java

...ainobjects/ltl/unittests/CounterExampleImplyUnitTest.java

...mainobjects/ltl/unittests/CounterExampleNextUnitTest.java

...omainobjects/ltl/unittests/CounterExampleNotUnitTest.java

...mainobjects/ltl/unittests/CounterExampleOnceUnitTest.java

...domainobjects/ltl/unittests/CounterExampleOrUnitTest.java

...nobjects/ltl/unittests/CounterExampleReleaseUnitTest.java

...ainobjects/ltl/unittests/CounterExampleSinceUnitTest.java

...nobjects/ltl/unittests/CounterExampleTriggerUnitTest.java

...ainobjects/ltl/unittests/CounterExampleUntilUnitTest.java

...bjects/ltl/unittests/CounterExampleWeakUntilUnitTest.java