Fixed #9: RandomWalkEQOracle and RandomWordsEQOracle now correctly deal with an empty inputs collection;
enhanced Javadoc for EquivalenceOracle interface
Some minor improvements (esp. documentation), added new EQ oracle
Merge branch 'develop' into reuse
Fixed bug in ParallelOracle
Merge branch 'develop' into reuse
removed unnecessary type args, systemstateinvalidation now not mandatory argument