This class represents a straight line segment between two points

Instance variables:
start <Point> start point of the line
end <Point> end point of the line

	converting
	asBezier2Segment asIntegerSegment asLineSegment

	initialize
	from:to:

	printing
	printOn:

	private
	debugDraw

	testing
	hasZeroLength isBezier2Segment isLineSegment isStraight

	vector functions
	length lineSegmentsDo: sideOfPoint: tangentAt: tangentAtEnd tangentAtStart valueAt: valueAtEnd valueAtStart

	accessing	top
	bounds Return the bounds containing the receiver
	direction
	end Return the end point
	start Return the start point

	converting	top
	asBezier2Segment Represent the receiver as quadratic bezier segment
	asIntegerSegment Convert the receiver into integer representation
	asLineSegment Represent the receiver as a straight line segment

	initialize	top
	from:to: Initialize the receiver

	printing	top
	printOn: Print the receiver on aStream

	private	top
	debugDraw

	testing	top
	hasZeroLength Return true if the receiver has zero length
	isBezier2Segment Return true if the receiver is a quadratic bezier segment
	isLineSegment Return true if the receiver is a line segment
	isStraight Return true if the receiver represents a straight line

	vector functions	top
	length Return the length of the receiver
	lineSegmentsDo: Evaluate aBlock with the receiver's line segments
	sideOfPoint: Return the side of the receiver this point is on. The method returns -1: if aPoint is left 0: if aPoint is on +1: if a point is right of the receiver.
	tangentAt: Return the tangent at the given parametric value along the receiver
	tangentAtEnd Return the tangent for the last point
	tangentAtStart Return the tangent for the last point
	valueAt: Evaluate the receiver at the given parametric value
	valueAtEnd Evaluate the receiver at it's end point (e.g., self valueAtEnd = (self valueAt: 1.0))
	valueAtStart Evaluate the receiver at it's start point (e.g., self valueAtEnd = (self valueAt: 0.0))

	instance creation	top
	from:to: