add stylesheet for QDateEdit widget
add stylesheet for QDateEdit widget

rdebroiz/medInria-public,rdebroiz/medInria-public,NicolasSchnitzler/medInria-public,aabadie/medInria-public,rdebroiz/medInria-public,NicolasSchnitzler/medInria-public,aabadie/medInria-public,NicolasSchnitzler/medInria-public,aabadie/medInria-public