1. Fixed parameters dialog javascript error.
2. Added check for deleted entities edge and face prior to processing. This fixes problems such as rayclark was having producing gcode and is an anomaly with sketchup that leaves deleted entities behind. 
3. Renamed Parameters Dialog tags "Safe Width" to "Safe Length" and "Safe Height" to "Safe Width" as per TigerPilot's suggestion.
4. Added menu item "Order Selected Edges" which will change the order of selected edges such that the edges form a continuous curve. This will help when trying to use the centerline tool on connected but disjointed edges.