- Scene PickArea(), PickPoint(), pickCollision() & PickRay() now accept an empty string for the group/layer masks to mean "all" groups/layers.  This is slightly better than having to use "-1" to mean all.
- Added "PickingToy" to show the different types of picking modes.  This toy only demonstrates "pickPoint()" but the alternate geometries of "pickArea()" and "pickRay()" work the same.