Re-add QT_USE_QTOPENGL.
Re-add QT_USE_QTOPENGL.

Required in order to obtain QT OpenGL context.

jcollfont/SCIRun,jessdtate/SCIRun,moritzdannhauer/SCIRunGUIPrototype,moritzdannhauer/SCIRunGUIPrototype,jessdtate/SCIRun,ajanson/SCIRun,jcollfont/SCIRun,collint8/SCIRun,ajanson/SCIRun,ajanson/SCIRun,ajanson/SCIRun,moritzdannhauer/SCIRunGUIPrototype,collint8/SCIRun,moritzdannhauer/SCIRunGUIPrototype,jcollfont/SCIRun,collint8/SCIRun,jessdtate/SCIRun,collint8/SCIRun,jessdtate/SCIRun,jessdtate/SCIRun,moritzdannhauer/SCIRunGUIPrototype,collint8/SCIRun,jcollfont/SCIRun,moritzdannhauer/SCIRunGUIPrototype,jessdtate/SCIRun,collint8/SCIRun,jcollfont/SCIRun,ajanson/SCIRun,jessdtate/SCIRun,ajanson/SCIRun,collint8/SCIRun,jcollfont/SCIRun,collint8/SCIRun,jcollfont/SCIRun,ajanson/SCIRun,jessdtate/SCIRun,moritzdannhauer/SCIRunGUIPrototype