Performance improvement: when a Schema is compared (equals) with itself it is not necessary compare all sub elements individually.
#191 Avoid inefficient List.minus() for non Comparable elements. Temporary fix without the need for equals and hashCode on all SchemaElements.
Performance improvement: the schema's are already unique by the algorithm in getImportedSchemas, and the unique comparison takes a lot of time.
Performance improvement: .intersect() uses the same inefficient code for non Comparable elements as the List.minus functionality.
Merge pull request #196 from ixorbe/safe-compare-performance-improvements

Compare algorithm performance improvements