fix for asserts added in own recent commit with more strict type-checking

- BMO_slot_copy now only copies compatible elements.

other minor changes
- don't use text.format(...), convention for UI scripts is C style string formatting.
- rename bmo_edgenet_prepare --> bmo_edgenet_prepare_exec
- float/double warning in bevel.

release/scripts/startup/bl_ui/properties_particle.py

@@ -148,7 +148,7 @@ class PARTICLE_PT_context_particles(ParticleButtonsPanel, Panel):
             #row.label(text="Render")
 
             if part.is_fluid:
-                layout.label(text="{} fluid particles for this frame".format(str(part.count)))
+                layout.label(text="%d fluid particles for this frame" % part.count)
                 return
 
             row = col.row()