Use VG read lock during 'pvscan --cache -aay' autoactivation.
Issue a VG refresh before autoactivation only if the PV has changed/is new.
Add flag to lvmetad protocol to indicate the PV scanned has changed/is new.
+ Also add vgname to lvmetad protocol when referencing VGs for PVs scanned.
Add man page for lvm2-activation-generator.
Don't print an error and accept empty value for global/thin_disabled_features.
Update API for internal function build_dm_uuid().