Levels of detail can be added and modified in the object panel. The object
panel also contains new tools for generating levels of detail, setting up
levels of detail based on object names (useful for importing), and
clearing an object's level of detail settings. This is meant as a game
engine feature, though the level of details settings can be previewed in
the viewport.
Reviewed By: moguri, nexyon, brecht
Differential Revision: http://developer.blender.org/D109
