Adding namespace to all evaluators and adapting clients

...Tools/ExpressionEvaluator/ExpressionEvaluator/Evaluator.h

...essionEvaluator/ExpressionEvaluator/ExpressionEvaluator.h

...ExpressionEvaluator/ExpressionEvaluator/ExprtkEvaluator.h

...ools/ExpressionEvaluator/ExpressionEvaluator/IEvaluator.h

GeoModelTools/ExpressionEvaluator/src/Evaluator.cxx

...odelTools/ExpressionEvaluator/src/ExpressionEvaluator.cxx

GeoModelTools/ExpressionEvaluator/src/ExprtkEvaluator.cxx

GeoModelTools/ExpressionEvaluator/src/setStdMath.cxx

GeoModelTools/ExpressionEvaluator/src/setSystemOfUnits.cxx

GeoModelTools/GDMLtoGM/GDMLInterface/GDMLController.h

GeoModelTools/GDMLtoGM/src/GDMLController.cxx

GeoModelTools/GDMLtoGM/src/constantHandler.cxx

GeoModelTools/GeoModelXML/GeoModelXml/GeoModelXml/Gmx2Geo.h

GeoModelTools/GeoModelXML/GeoModelXml/GeoModelXml/GmxUtil.h

...Tools/GeoModelXML/GeoModelXml/GeoModelXml/PositionIndex.h

GeoModelTools/GeoModelXML/GeoModelXml/src/Gmx2Geo.cxx

GeoModelTools/GeoModelXML/GeoModelXml/src/GmxUtil.cxx

GeoModelTools/GeoModelXML/GeoModelXml/src/PositionIndex.cxx