- Upgraded parent project version: 6.0.0 -> 7.0.0

- Upgraded dependencies: core-pdp-api: 11.0.0 ->12.0.0
- Changed PDP XSD: 5.0.0 -> 6.0.0
	- Attribute badRequestStatusDetailLevel ->
clientRequestErrorVerbosityLevel
	- Attribute requestFilter/resultFilter attributes -> element
ioProcChain* (InOutProcChain: pair of request/response processors)
	- Added maxIntegerValue attribute to help the PDP engine optimize
processing of integer values (choice between Java integer
implementations, i.e. BigInteger, Long, Integer)
- Changed naming convention for class names with acronym(s) (only first
letter should be uppercase), e.g. PolicyPOJO -> PolicyPojo	
- Added module pdp-cli for PDP command-line interface, produces an
executable jar allowing to test PDP engine on the command line
- Added module pdp-io-xacml-json for PDP extensions processing
(request/result pre/postprocessors) formats defined by JSON Profile of
XACML 3.0, with OASIS XACML 3.0 conformance tests auto-converted (from
XML) to JSON; therefore also provides XSLT sheets for transforming
XACML/XML requests/responses to XACML/JSON
- Adapted BasePdpEngine to new PdpEngine interface, i.e. agnostic of
serialization format, e.g. XACML/XML specific part moved to separate
PdpEngineInoutAdapter implementation
- XACML/JAXB RequestFilters become RequestPreprocessors:
	- DefaultRequestFilter -> SingleDecisionXacmlJaxbRequestPreprocessor
	- MultiDecisionRequestFilter ->
MultiDecisionXacmlJaxbRequestPreprocessor
- PdpEngineAdapters utility class to help instantiate
XACML/JAXB-supporting PDP engines
- Added PdpEngineConfiguration utility class to simplify instantiation
of BasePdpEngine from pdp.xml
- Renamed PdpExtensionLoader -> PdpExtensions
- Renamed CoreRefBasedRootPolicyProviderModule ->
CoreRefBasedRootPolicyProvider
- Renamed CoreRefPolicyProviderModule -> CoreRefPolicyProvider
- Renamed CoreRootPolicyProviderModule -> CoreRootPolicyProvider
- Renamed MongoDBRefPolicyProviderModule -> MongoDbRefPolicyProvider
- StaticApplicablePolicyView -> FlattenedPolicyTree
- ImmutableDatatypeFactoryRegistry ->
ImmutableAttributeValueFactoryRegistry
- StandardDatatypeFactoryRegistry -> StandardAttributeValueFactories
- PDP extensions