Add support for saving ALDB_Delta

Add basic code for storing and saving the ALDB_Delta.

Copied Michael's removal of the double level state save.
Enable Skipping Unchanged Devices in Scan All Linkes

- Request status at the completion of any scan and store ALDB Delta
- Alter Scan All Links to enable skipping unchanged devices
-- For each device a Status Request is made
-- If the ALDB Delta has not changed, skip scanning the device
-- If the ALDB Delta has changed scan the entire device and store the new ALDB Delta record
-- The Scan Link Table Voice Cmd for each device still forces a scan
Merge branch 'aldb_delta' into running