Ruled Surface: strips off an edge chain, exact where possible (#762) (#1151)

Ruled Surface: strips off an edge chain in normal, tangent, angle or direction mode, exact planes/cylinders/cones where possible, mitred or round corners, stitched into one surface body. SurfaceRuled is noted under format 21. Closes #762.

assets/locales/de.json

@@ -851,5 +851,10 @@
   "In place (surfaces)": "An Ort und Stelle (Flächen)",
   "None": "Keine",
   "Picked": "Ausgewählte",
-  "Restore outer boundary": "Äußere Begrenzung wiederherstellen"
+  "Restore outer boundary": "Äußere Begrenzung wiederherstellen",
+  "RULED SURFACE": "REGELFLÄCHE",
+  "Mitre": "Gehrung",
+  "Reference face": "Referenzfläche",
+  "Round": "Rund",
+  "Type": "Typ"
 }