#194 Avoiding wrong exchange matching in WsdlDiffGenerator.comparePortTypes
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: caching type lookups in Schema
Performance improvement: caching the results of getAllSchemas(). This results in dramatic performance improvements for larger type trees build out of multiple schemas.
#194 exchange is now a String value and not a Collection
Performance improvement: .intersect() uses the same inefficient code for non Comparable elements as the List.minus functionality.
Merge pull request #197 from ixorbe/compare-performance-improvements-through-caching

Compare performance improvements through caching

Thanks again for your contribution!
Merge pull request #196 from ixorbe/safe-compare-performance-improvements

Compare algorithm performance improvements
Merge pull request #195 from ixorbe/194-NullPointerException-in-WsdlDiffGenerator

#194 Avoiding wrong exchange matching in WsdlDiffGenerator.comparePortTypes