use set as a suffix (matches operators)

- set_frame() --> frame_set()
 - set_context_pointer() --> context_pointer_set()

material adding works for curves and metaballs, new function to remove materials.

materials.link() didnt well fit how this is used elsewhere
 - order matters
 - it can be linked more than once.
 - remove(material), isnt that useful since you need to manage indicies.

... use list style functions instead. materials.append(mat) / materials.pop(index)

release/scripts/ui/properties_physics_common.py

@@ -26,7 +26,7 @@ import bpy
 def point_cache_ui(self, context, cache, enabled, cachetype):
     layout = self.layout
 
-    layout.set_context_pointer("point_cache", cache)
+    layout.context_pointer_set("point_cache", cache)
 
     row = layout.row()
     row.template_list(cache, "point_caches", cache.point_caches, "active_index", rows=2)