toolhead: Specify maximum acceleration and velocity in toolhead class

Change the config file so the maximum accel and velocity are specified
in the "printer" section instead of the individual "stepper" sections.
The underlying code limits the velocity and accel of the toolhead
relative to the print object, so it makes sense to configure the
system that was as well.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/delta.py

@@ -28,17 +28,14 @@ class DeltaKinematics:
             (cos(210.)*radius, sin(210.)*radius),
             (cos(330.)*radius, sin(330.)*radius),
             (cos(90.)*radius, sin(90.)*radius)]
-    def build_config(self):
+    def set_max_jerk(self, max_xy_halt_velocity, max_accel):
+        # XXX - this sets conservative values
         for stepper in self.steppers:
-            stepper.set_max_jerk(0.005 * stepper.max_accel) # XXX
+            stepper.set_max_jerk(max_xy_halt_velocity, max_accel)
+    def build_config(self):
         for stepper in self.steppers:
             stepper.build_config()
         self.set_position([0., 0., 0.])
-    def get_max_speed(self):
-        # XXX - this returns conservative values
-        max_xy_speed = min(s.max_velocity for s in self.steppers)
-        max_xy_accel = min(s.max_accel for s in self.steppers)
-        return max_xy_speed, max_xy_accel
     def cartesian_to_actuator(self, coord):
         return [int((math.sqrt(self.arm_length2
                                - (self.towers[i][0] - coord[0])**2