Qt / Cpp: Port auto_ptr to unique_ptr
* lang/cpp/src/context.cpp, lang/cpp/src/context.h, lang/cpp/src/context_p.h (Context::createForEngine), (Context::edit, Context::startEditing), (Context::takeLastEditInteractor, Context::cardEdit), (Context::startCardEditing, Context::takeLastCardEditInteractor), (Context::assuanTransact, Context::startAssuanTransaction), (Context::takeLastAssuanTransaction): Port to unique_ptr. * lang/qt/src/qgpgmeadduseridjob.cpp, lang/qt/src/qgpgmechangeexpiryjob.cpp, lang/qt/src/qgpgmechangeownertrustjob.cpp, lang/qt/src/qgpgmechangepasswdjob.cpp, lang/qt/src/qgpgmesignkeyjob.cpp: Update accordingly.
This is another API break but as we already broke API with GpgME++
and QGpgME from KDE Frameworks this is a good time to do this
to avoid using a deprected C++ class in the API.