Declare EnvironmentVariable class according to standard conventions.
Declare EnvironmentVariable class according to standard conventions.

Change-Id: Ib8e8da8d56aa6d7f17d7e2ec138a518219febb9a
Reviewed-by: Joerg Bornemann <47777b9406dbddd02a3fdca8341789a013805a11@digia.com>

Distrotech/qbs,Distrotech/qbs,Distrotech/qbs,gatzka/qt-labs-qbs,qt-labs/qbs,gatzka/qt-labs-qbs,gatzka/qt-labs-qbs,qt-labs/qbs,Distrotech/qbs,qtproject/qt-labs-qbs,villytiger/qbs,villytiger/qbs,gatzka/qt-labs-qbs,Distrotech/qbs,qt-labs/qbs,qt-labs/qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,villytiger/qbs,qtproject/qt-labs-qbs,Distrotech/qbs,Distrotech/qbs,qt-labs/qbs,villytiger/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,villytiger/qbs,qt-labs/qbs,villytiger/qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs