-other joins
-quiet bits
-add new `silently' directive or something, as mustn't use layers in parts
-don't use layers in parts
+race between cdu off (due to watchdog or short) and points
+
+
+layout polarity diagram colourful segment encoding:
+ make moveable feature selection in subseg2display bitwise rather than
+ setwise
+
+safety system no crashes at crossovers please