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/toolhead.py

@@ -162,7 +162,8 @@ class ToolHead:
         kintypes = {'cartesian': cartesian.CartKinematics,
                     'delta': delta.DeltaKinematics}
         self.kin = config.getchoice('kinematics', kintypes)(printer, config)
-        self.max_speed, self.max_accel = self.kin.get_max_speed()
+        self.max_speed = config.getfloat('max_velocity')
+        self.max_accel = config.getfloat('max_accel')
         self.junction_deviation = config.getfloat('junction_deviation', 0.02)
         self.move_queue = MoveQueue()
         self.commanded_pos = [0., 0., 0., 0.]
@@ -176,6 +177,7 @@ class ToolHead:
         self.motor_off_time = self.reactor.NEVER
         self.flush_timer = self.reactor.register_timer(self.flush_handler)
     def build_config(self):
+        self.kin.set_max_jerk(0.005 * self.max_accel, self.max_accel) # XXX
         self.kin.build_config()
     # Print time tracking
     def update_move_time(self, movetime):