Always use detailed shape for physics raycasts
Currently the shapes used for physics raycasts are the same as the collision shapes, which causes wrong results for example in object pickup and placement on shelves, which use a box as collision shape. For raytests, the more detailed shape (the same as the one used for rendering) should always be used.
For object pickup, we are currently working around this by "abusing" occlusion queries for this purpose. However this cannot work for object placement. Once this is fixed, the occlusion query hack can be removed.
(RM-387 from redmine: created on 2012-08-29 by scrawl ., , closed on 2013-03-09 by scrawl ., duplicates #429 (closed), duplicates #519 (closed))