Fix text wrapping and several other style issues of the About dialog
Fix text wrapping and several other style issues of the About dialog

Contributes to Ultimaker/Uranium#43

bq/Ultimaker-Cura,totalretribution/Cura,Curahelper/Cura,hmflash/Cura,totalretribution/Cura,quillford/Cura,ynotstartups/Wanhao,senttech/Cura,fieldOfView/Cura,quillford/Cura,DeskboxBrazil/Cura,ad1217/Cura,markwal/Cura,ad1217/Cura,ynotstartups/Wanhao,lo0ol/Ultimaker-Cura,fxtentacle/Cura,derekhe/Cura,derekhe/Cura,DeskboxBrazil/Cura,fxtentacle/Cura,bq/Ultimaker-Cura,Curahelper/Cura,hmflash/Cura,lo0ol/Ultimaker-Cura,senttech/Cura,fieldOfView/Cura,markwal/Cura