Recreate editingFinished signal behaviour without using TextArea::editingFinished
Recreate editingFinished signal behaviour without using TextArea::editingFinished

Apparently, editingFinished was only added in Qt 5.6, so we cannot use
it. So we have to manually recreate the behaviour.

Contributes to CURA-342

fieldOfView/Cura,hmflash/Cura,ynotstartups/Wanhao,ynotstartups/Wanhao,senttech/Cura,fieldOfView/Cura,hmflash/Cura,Curahelper/Cura,Curahelper/Cura,totalretribution/Cura,senttech/Cura,totalretribution/Cura