Add legacy beatmap flag.
Taiko hitobject base
When dragging music controller we divide by the dragged distance. When dragging to the origin of the drag this resulted in NaN. Now, we check for this and use 0 in this case.
Conflicts: osu.Game/Beatmaps/Legacy/IIsLegacy.cs
Song select performance / code cleanup.
Add menu cursor.
Add reading of KiaiMode/OmitFirstBarLine from legacy control points.