Zeroable

Zeroable is used at run time in 4 crates (of which 1 optionally). It is a direct run-time dependency in 3 crates.

Depender (with downloads and own rev deps)			Zeroable version
	2	netlistdb		^0.2.0
		logiclib		^0.2.0
		stagraph		^0.2.0