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
bringing back the accidentally deleted test
adding log4j config file for the unit tests
introduced interfaces for conclusions; added generic parameters for
subsumers -> killed some casts; added missing generic parameters; killed
all warnings to easier find new ones
new files missing from the previous commit
Merge branch 'master' into feature/tracing-review
bringing back the tracing completeness checks
tweaks to the elk-protege's pom to specify correct version restrictions
in the manifest regardless of what the protege's pom say
Merge branch 'master' of https://github.com/klinovp/elk
NonRedundantRuleApplicationConclusionVisitor implemented directly using
Conclusion interfaces; refined some generic parameters in visitors using
the ? super C wildcard.
finished moving rule application methods to visitors over conclusions.
Visitors can now be composed with "null" visitors, which are ignored
(useful for switching off some visitors). Using this strategy for
counting processed / used conclusions.
HybridLocalRuleApplicationConclusionVisitor slightly simplified
some simplification for conclusion visitors; printing produced
conclusion counts
* tracing support for contradictions, bottom, disjunctions, negations,
and disjoint classes.
* comprehensive tracing tests (test tracing of each atomic
subsumption/unsatisfiability in all our test ontologies).