[x0d] simplify optimization levels. default to all[currently available] or nothing (for now)
[x0d] simplify optimization levels. default to all[currently available] or nothing (for now)

xzero/x0,christianparpart/x0,christianparpart/x0,christianparpart/x0,christianparpart/x0,christianparpart/x0,christianparpart/x0,xzero/x0,xzero/x0,xzero/x0,christianparpart/x0,xzero/x0,xzero/x0