Ramp grid types

Variables
const int	Renga::GridTypes::Ramp::BackSide = 4
	Side face of a ramp at the end where the ramp building has been finished.
const int	Renga::GridTypes::Ramp::Bottom = 2
	Bottom face of a ramp.
const int	Renga::GridTypes::Ramp::Cut = 7
	Faces appearing as a result of cutting a ramp by other objects.
const int	Renga::GridTypes::Ramp::FrontSide = 3
	Side face of a ramp at the end where the ramp building has been started.
const int	Renga::GridTypes::Ramp::LeftSide = 5
	Left side face of a ramp (when looking at the front face)
const int	Renga::GridTypes::Ramp::RightSide = 6
	Right side face of a ramp (when looking at the front face)
const int	Renga::GridTypes::Ramp::Top = 1
	Top face of a ramp.
const int	Renga::GridTypes::Ramp::Undefined = 0
	Undefined.

Possible grid types for a Ramp mesh