GEOT-4386 SchemaFactory getInstance methods very slow on some XSD used by Inspire
GEOT-4386 removed dependencies from app-schema resolver
GEOT-4386 Removed duplicated classes in app-schema-resolver, added gt-xml dependency to app-schema and gt-complex, updated gt-xml review file, introduced synchronization in SchemaCache
GEOT-4386 updated docs, enhanced synchronization on SchemaResolver
Merge pull request #135 from mbarto/geot_4386_no_app_schema_resolver

GEOT-4386 SchemaFactory in gt-xml can be very slow downloading xsd