[bugfix] Fixed segfault introduced in #594:
PointCloudRenderable simply inherits world transform from parent.
[bugfix] #595 BoolProperty: Displays, Groups disable their children when their bool value is false (as before), default behaviour is not to do that (as in Fuerte RViz). Fixes issues with weird layout of properties in Point Cloud Transformers, where a propery has editable subproperties when it is set to false, e.g. the 'use rainbow' property for intensity coloring.