replace relative imports with absolute imports so scritps can be executed directly (live editing).

release/scripts/startup/bl_ui/properties_particle.py

@@ -21,7 +21,7 @@ import bpy
 from bpy.types import Panel
 from rna_prop_ui import PropertyPanel
 
-from .properties_physics_common import (
+from bl_ui.properties_physics_common import (
     point_cache_ui,
     effector_weights_ui,
     basic_force_field_settings_ui,