rename connectingBar to yBar, and add mockup of new xBar. Also mess around with the full assembly

helper/sphericalFilet.scad

@@ -0,0 +1,15 @@
+
+module sphericalFiletEdge(width, depth, height, roundness) {
+  rd = roundness;
+
+  intersection() {
+    minkowski() {
+      sphere(r = rd);
+
+      translate(v = [rd, rd, rd])
+      cube(size = [width*2, depth - 2*rd, height*2]);
+    }
+
+    cube(size = [width, depth, height]);
+  }
+}