textproc/jade: unbreak build with Clang 6 (C++14 by default)

In file included from EntityCatalog.cxx:9:
In file included from ./../include/EntityDecl.h:12:
./../include/Ptr.h:73:11: error: ISO C++11 does not allow access declarations; use using declarations

    instead
Ptr<T>::isNull;
        ^
using

./../include/Ptr.h:74:11: error: ISO C++11 does not allow access declarations; use using declarations

    instead
Ptr<T>::clear;
        ^
using

In file included from DescriptorManager.cxx:5:
In file included from ./../include/DescriptorManager.h:8:
In file included from ./../include/List.h:7:
./../include/IList.h:29:14: error: ISO C++11 does not allow access declarations; use using

    declarations instead
IListBase::clear;
           ^
using

./../include/IList.h:30:14: error: ISO C++11 does not allow access declarations; use using

    declarations instead
IListBase::empty;
           ^
using

In file included from DescriptorManager.cxx:6:
In file included from ./../include/ListIter.h:8:
./../include/IListIter.h:20:18: error: ISO C++11 does not allow access declarations; use using

    declarations instead
IListIterBase::next;
               ^
using

./../include/IListIter.h:21:18: error: ISO C++11 does not allow access declarations; use using

    declarations instead
IListIterBase::done;
               ^
using

In file included from parseSd.cxx:5:
./Parser.h:65:16: error: ISO C++11 does not allow access declarations; use using declarations instead

ParserState::sdPointer;
             ^
using

./Parser.h:66:16: error: ISO C++11 does not allow access declarations; use using declarations instead

ParserState::instanceSyntaxPointer;
             ^
using

./Parser.h:67:16: error: ISO C++11 does not allow access declarations; use using declarations instead

ParserState::prologSyntaxPointer;
             ^
using

./Parser.h:68:16: error: ISO C++11 does not allow access declarations; use using declarations instead

ParserState::activateLinkType;
             ^
using

./Parser.h:69:16: error: ISO C++11 does not allow access declarations; use using declarations instead

ParserState::allLinkTypesActivated;
             ^
using

./Parser.h:70:16: error: ISO C++11 does not allow access declarations; use using declarations instead

ParserState::entityManager;
             ^
using

./Parser.h:71:16: error: ISO C++11 does not allow access declarations; use using declarations instead

ParserState::entityCatalog;
             ^
using

./Parser.h:72:16: error: ISO C++11 does not allow access declarations; use using declarations instead

ParserState::baseDtd;
             ^
using

./Parser.h:73:16: error: ISO C++11 does not allow access declarations; use using declarations instead

ParserState::options;
             ^
using

PR: 224929
Reported by: antoine (via bug 224669)
Reviewed by: dim
Approved by: portmgr blanket