Don't unnecessarily remove from backup objects that were not directly attached from the scene.

These are never in region backup in the first place since recent 11830c43
Extend regression test to check backup status.
Add "debug lludp throttle log <level> <avatar-first-name> <avatar-last-name>" to control extra throttle related debug logging.
Add "debug lludp throttle status" command to return status information about a client's throttle (currently just whether adaptive is enabled).
Add "debug lludp throttle set" command to allow setting of parameters at runtime

Can currently only set adaptive true|false, where adaptive = false
refactor: rename "debug lludp throttle status" to "debug lludp throttle get" to match set command