Blender Git Loki

UI: simplify tool-tip logic for operators

- Use WM_operatortype_description to get the operator description.
- Pass properties to WM_operatortype_name,
so the operator name callback is used.
- Add UI_but_operatortype_get_from_enum_menu function
to access the operator from enum menus.
- Change WM_operatortype_description to return NULL when there is no
description, use WM_operatortype_description_or_name
when either can be used.