enable bedbolts for Straight 'e' and OutSet edges 'E'

note that this mostly ignores that positioning bedbolts is done
in the BedBolt class for finger joints.
Coding style could be much improved.

boxes/edges.py

@@ -294,16 +294,31 @@ class Edge(BaseEdge):
     """Straight edge"""
     char = 'e'
     description = "Straight Edge"
+    positive = False
 
     def __call__(self, length, bedBolts=None, bedBoltSettings=None, **kw):
         """Draw edge of length mm"""
-        self.edge(length, tabs=2)
+        if bedBolts:
+            # distribute the bolts aequidistantly
+            interval_length = length / bedBolts.bolts
+            if self.positive:
+                d = (bedBoltSettings or self.bedBoltSettings)[0]
+                for i in range(bedBolts.bolts):
+                    self.hole(0.5 * interval_length,
+                              0.5 * self.thickness, 0.5 * d)
+                    self.edge(interval_length, tabs=2)
+            else:
+                for i in range(bedBolts.bolts):
+                    self.bedBoltHole(interval_length, bedBoltSettings)
+        else:
+            self.edge(length, tabs=2)
 
 
 class OutSetEdge(Edge):
     """Straight edge out set by one thickness"""
     char = 'E'
     description = "Straight Edge (outset by thickness)"
+    positive = True
 
     def startwidth(self):
         return self.boxes.thickness