Data manipulation tools

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	Class	Description
	Circularise	Tool to transform a closed way of at least 3 distinct points into a circular shape, inserting more nodes as necessary.
	Parallelise	Tool to create a parallel copy of an existing way.
	Quadrilateralise	Tool to transform a closed way by making corners right-angled, if possible.
	Simplify	Tool to reduce the number of nodes in a way by filtering out the "least important" ones, using the Douglas-Peucker algorithm.
	Straighten	Tool to transform a non-closed way into a straight line, by deleting any non-junction, untagged, on-screen nodes, and moving the others to fit.