Allowing pinned materials to be changed from the topbar. We previously disabled this, as there was no reasonable way to have the object material slot selector and the brush material property not looking entirely differently.
I changed uiTemplateList to be able to work with active pointer and index. This allows to display bpy.data.materials while highlighting the brush material. When a item in the list gets selected but->funcN will set the value of but->rnaprop (active property) to but->func_argN (represented item). For lists with active index everything is working as before.