Also restructures with the addition of a ManiaBeatmap which holds definitions for "groups" of columns. At the moment these are empty save for a "Column" property, but can be expanded in the future, maybe.
# Conflicts: # osu.Game.Rulesets.Mania/Beatmaps/ManiaBeatmapConverter.cs # osu.Game.Rulesets.Mania/UI/ManiaRulesetContainer.cs # osu.Game/Rulesets/UI/RulesetContainer.cs