Particles: child editing bugfixes

* Make partial update work again for faster editing.
* Draw parents over children again, nicer for editing.
* Fix crash with remove tools & showing child particles.
* Fix children not disappearing always when setting to None.
* Fix wrong normal for last point in child path.
* Fix a python error in the hair dynamics panel.

release/scripts/ui/properties_particle.py

@@ -208,6 +208,10 @@ class PARTICLE_PT_hair_dynamics(ParticleButtonsPanel):
         layout = self.layout
 
         psys = context.particle_system
+
+        if not psys.cloth:
+            return
+
         #part = psys.settings
         cloth = psys.cloth.settings
 
@@ -298,8 +302,8 @@ class PARTICLE_PT_velocity(ParticleButtonsPanel):
         sub.prop(part, "random_factor")
 
         #if part.type=='REACTOR':
-        #	sub.prop(part, "reactor_factor")
-        #	sub.prop(part, "reaction_shape", slider=True)
+        #    sub.prop(part, "reactor_factor")
+        #    sub.prop(part, "reaction_shape", slider=True)
 
 
 class PARTICLE_PT_rotation(ParticleButtonsPanel):