bug (old): STILL can't focus cam through HUD attachments

Steps to reproduce the bug: Create a prim, wear it as a HUD attachment, and try to focus the camera (alt+left-click) on something behind the HUD attachment.

Observed results: nothing

Expected results: The camera should focus THROUGH the HUD attachment and not be obscured by it.

Note: if the HUD attachment is selected and alt-focused on (then zoomed in/out), the attachment will scale accordingly. While this is nice for SELECTED HUD attachments, UNSELECTED HUD attachments should be phantom to camera focus/zooming.