Revert "If NUD is ReadOnly then HideUpDownButtons is set to true"
Revert "If NUD is ReadOnly then HideUpDownButtons is set to true"

This reverts commit bb311c6c7b21ae9f207bc8991be08b755742153b.

chuuddo/MahApps.Metro,xxMUROxx/MahApps.Metro,batzen/MahApps.Metro,Jack109/MahApps.Metro,pfattisc/MahApps.Metro,p76984275/MahApps.Metro,psinl/MahApps.Metro,MahApps/MahApps.Metro,ye4241/MahApps.Metro,Evangelink/MahApps.Metro,jumulr/MahApps.Metro,Danghor/MahApps.Metro