Eliminate usage of QScriptEngine for JSON parsing
Eliminate usage of QScriptEngine for JSON parsing

QJsonDocument is lighter alternative for this task.

Change-Id: I642f6cf04ce04aa40002460f0519334f92fc54c3
Reviewed-by: Jake Petroules <2d627e1cecd5435752fa500bacbe05f7cc90c369@petroules.com>

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