Also removing a lot of mania code relating to gravity mod for now.
Depends on https://github.com/ppy/osu-framework/pull/837
# Conflicts: # osu-framework
# Conflicts: # osu-framework # osu.Game.Rulesets.Mania/Timing/ControlPointContainer.cs
Also includes commenting improvements/fixes.
# Conflicts: # osu.Game.Rulesets.Mania/UI/Column.cs