pvs, pvscan: new option -A to show PVs outside the devices file

pvs, pvscan: new option -A to show PVs outside the devices file

pvs -A|--allpvs
	Show PVs that would otherwise be excluded by the devices file.

pvscan -A|--allpvs
	Show PVs that would otherwise be excluded by the devices file.
	For those devices that are included by the devices file,
	their device ID is displayed in place of the usual "lvm2"
	format and size.

(pvs -a|--all is unchanged, and shows devices not formatted as PVs.)