optimization checking redundancy of rule compositions
Producing backward links from forward links instead of other way round.
Forward links are now over (possibly complex) property chains, whereas
backward links are over object properties. Hence composition tables in
saturation are computed only between atomic and (possibly complex)
property chains. Some cleaning up: removed / hardcoded parameter options
for property saturations since they do not apply anymore.
Merge branch 'master' into feature/optimized-role-composition

Conflicts:
	elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/ContextImpl.java
	elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/context/ContextPremises.java
	elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/context/HybridContextPremises.java
	elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/rules/backwardlinks/BackwardLinkChainFromBackwardLinkRule.java
	elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/rules/backwardlinks/ForwardLinkFromBackwardLinkRule.java
	elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/rules/forwardlink/NonReflexiveBackwardLinkCompositionRule.java
	elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/rules/forwardlink/ReflexiveBackwardLinkCompositionRule.java
	elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/rules/propagations/ReflexivePropagationRule.java
	elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/rules/subsumers/IndexedObjectSomeValuesFromDecomposition.java
	elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/rules/subsumers/PropagationFromExistentialFillerRule.java