cpp, qt: Include config.h

lang/cpp/src/callbacks.cpp,
lang/cpp/src/configuration.cpp,
lang/cpp/src/context.cpp,
lang/cpp/src/context_glib.cpp,
lang/cpp/src/context_qt.cpp,
lang/cpp/src/context_vanilla.cpp,
lang/cpp/src/data.cpp,
lang/cpp/src/decryptionresult.cpp,
lang/cpp/src/defaultassuantransaction.cpp,
lang/cpp/src/editinteractor.cpp,
lang/cpp/src/encryptionresult.cpp,
lang/cpp/src/engineinfo.cpp,
lang/cpp/src/eventloopinteractor.cpp,
lang/cpp/src/exception.cpp,
lang/cpp/src/gpgadduserideditinteractor.cpp,
lang/cpp/src/gpgagentgetinfoassuantransaction.cpp,
lang/cpp/src/gpgsetexpirytimeeditinteractor.cpp,
lang/cpp/src/gpgsetownertrusteditinteractor.cpp,
lang/cpp/src/gpgsignkeyeditinteractor.cpp,
lang/cpp/src/importresult.cpp,
lang/cpp/src/key.cpp,
lang/cpp/src/keygenerationresult.cpp,
lang/cpp/src/keylistresult.cpp,
lang/cpp/src/scdgetinfoassuantransaction.cpp,
lang/cpp/src/signingresult.cpp,
lang/cpp/src/tofuinfo.cpp,
lang/cpp/src/trustitem.cpp,
lang/cpp/src/verificationresult.cpp,
lang/cpp/src/vfsmountresult.cpp,
lang/qt/src/dataprovider.cpp,
lang/qt/src/defaultkeygenerationjob.cpp,
lang/qt/src/gpgme_backend_debug.cpp,
lang/qt/src/job.cpp,
lang/qt/src/qgpgmeadduseridjob.cpp,
lang/qt/src/qgpgmebackend.cpp,
lang/qt/src/qgpgmechangeexpiryjob.cpp,
lang/qt/src/qgpgmechangeownertrustjob.cpp,
lang/qt/src/qgpgmechangepasswdjob.cpp,
lang/qt/src/qgpgmedecryptjob.cpp,
lang/qt/src/qgpgmedecryptverifyjob.cpp,
lang/qt/src/qgpgmedeletejob.cpp,
lang/qt/src/qgpgmedownloadjob.cpp,
lang/qt/src/qgpgmeencryptjob.cpp,
lang/qt/src/qgpgmeexportjob.cpp,
lang/qt/src/qgpgmeimportfromkeyserverjob.cpp,
lang/qt/src/qgpgmeimportjob.cpp,
lang/qt/src/qgpgmekeyformailboxjob.cpp,
lang/qt/src/qgpgmekeygenerationjob.cpp,
lang/qt/src/qgpgmekeylistjob.cpp,
lang/qt/src/qgpgmelistallkeysjob.cpp,
lang/qt/src/qgpgmenewcryptoconfig.cpp,
lang/qt/src/qgpgmerefreshkeysjob.cpp,
lang/qt/src/qgpgmesecretkeyexportjob.cpp,
lang/qt/src/qgpgmesignencryptjob.cpp,
lang/qt/src/qgpgmesignjob.cpp,
lang/qt/src/qgpgmesignkeyjob.cpp,
lang/qt/src/qgpgmetofupolicyjob.cpp,
lang/qt/src/qgpgmeverifydetachedjob.cpp,
lang/qt/src/qgpgmeverifyopaquejob.cpp,
lang/qt/src/qgpgmewkspublishjob.cpp,
lang/qt/src/threadedjobmixin.cpp,
lang/qt/tests/run-keyformailboxjob.cpp,
lang/qt/tests/t-encrypt.cpp,
lang/qt/tests/t-keylist.cpp,
lang/qt/tests/t-keylocate.cpp,
lang/qt/tests/t-ownertrust.cpp,
lang/qt/tests/t-support.cpp,
lang/qt/tests/t-tofuinfo.cpp,
lang/qt/tests/t-wkspublish.cpp: Include config.h

This fixes problems with mismatching definitions. Most
notably _FILE_OFFSET_BITS is now always set correctly.