pstd

pstd is used at run time in 4 crates (of which 2 optionally).

Depender (with downloads and own rev deps)			pstd version
	3	rustdb		^1.0.0
		rustweb2		^1.0.0
	2	atom-file	optional	^1.0.0
	1	page-store	optional	^1.0.0