Add support for JEP-185 (JAXP-1.5) properties named `ACCESS_EXTERNAL_` about woodstox HOT 4 OPEN

JAXP 1.5 adds three new API-level properties to limit external connections to specific, named protocols:

javax.xml.XMLConstants.ACCESS_EXTERNAL_DTD: A list of protocols by which external DTDs and external entity references may be accessed.

javax.xml.XMLConstants.ACCESS_EXTERNAL_SCHEMA: A list of protocols via which external schema references, specified by the schemaLocation attribute of import and include elements, may be resolved.

javax.xml.XMLConstants.ACCESS_EXTERNAL_STYLESHEET: A list of protocols via which external references specified in stylesheet constructs such as processing instructions, document() functions, import elements, and include elements may be resolved.

It also adds three corresponding system properties, to provide developers the ability to change the settings without changing code:

javax.xml.accessExternalDTD for ACCESS_EXTERNAL_DTD

javax.xml.accessExternalSchema for ACCESS_EXTERNAL_SCHEMA

javax.xml.accessExternalStylesheet for ACCESS_EXTERNAL_STYLESHEET

Finally, it allows the above properties to be set in the existing configuration file, ${java.home}/lib/jaxp.properties, so as to define the behavior for all invocations of the JDK or JRE. The format of entries in the file is property-name=value, for example:

javax.xml.accessExternalDTD=file,http