Three fixes, thanks to irc reporting of Basse & Sten;

- Bone points for B-Bone drawing were not adjusted for size of Bone, now
  they draw same size as for other bone type
- Deleting bones in editmode didn't check for constraints in Pose, causing
  weird collapsed poses or even crashes
- ALT+S scaling on B-Bones in editmode didn't correct for the Object scale.

source/blender/src/transform.c

@@ -2227,7 +2227,7 @@ static void ElementBoneSize(TransInfo *t, TransData *td, float mat[3][3])
 	/* we've tucked the scale in loc */
 	oldy= td->iloc[1];
 	SizeToMat3(td->iloc, sizemat);
-	Mat3MulMat3(tmat, smat, sizemat);
+	Mat3MulMat3(tmat, tmat, sizemat);
 	Mat3ToSize(tmat, td->loc);
 	td->loc[1]= oldy;
 }