Pipe should have a method to create an assembly

[gumyr]

When creating a bill of materials from a complex pipe each segment should be individually accessible. In addition, to enable space for welds, a carbon steel pipe segments would have a 1/16" gap between them (while the gap for stainless is 0").

To achieve this:

1. The path needs to be stored in an instance variable such that the Edges can be extracted from the path.
2. A new method should return a assembly of segmented pipe based on the path Edges and optionally slice off the ends of each segment to generate a gap between them.