Draft: Fix Draft_PointArray and Draft_TwistedArray Count problems

Draft_PointArray and Draft_TwistedArray have Count problems:
1. Draft_PointArray: Count is always zero.
2. Draft_PathTwistedArray: Number of items is Count+1.
3. Draft_PathTwistedLinkArray: Count is increased whenever object is recomputed.

Also the first item in a twisted array should be unrotated.

src/Mod/Draft/draftgeoutils/geo_arrays.py

@@ -64,8 +64,8 @@ def get_init_values(path, count=6):
     edge = path.Shape.Edges[0]
     edge_length = edge.Length
 
-    step = edge_length / count
-    inc = 360/count
+    step = edge_length / (count - 1)
+    inc = 360 / (count - 1)
 
     return norm, edge, step, inc
 
@@ -91,16 +91,17 @@ def get_twisted_placements(path, count=15, rot_factor=0.25):
     places = []
     params = []
 
-    for number in range(count + 1):
+    for number in range(count):
         v0, tan, rot = get_n_params(edge, number, step, norm)
 
-        increment += inc
         angle = increment * rot_factor
         place = App.Placement(v0, tan, angle)
         place.Rotation = place.Rotation * rot
         places.append(place)
 
         params.append((v0, tan, angle, rot))
+        
+        increment += inc
 
     return places, params