Added an option in the IK constraint to disable stretching, useful

in rigs with layered IK constraints. Also removed the tolerance
setting, this value wasn't used in the solver anymore.

source/blender/blenkernel/intern/constraint.c

@@ -563,10 +563,10 @@ void *new_constraint_data (short type)
 			bKinematicConstraint *data;
 			data = MEM_callocN(sizeof(bKinematicConstraint), "kinematicConstraint");
 
-			data->tolerance = (float)0.001;
 			data->weight= (float)1.0;
+			data->orientweight= (float)1.0;
 			data->iterations = 500;
-			data->flag= CONSTRAINT_IK_TIP;
+			data->flag= CONSTRAINT_IK_TIP|CONSTRAINT_IK_STRETCH|CONSTRAINT_IK_POS;
 			
 			result = data;
 		}