mwc_util

mwc_util is used at run time in 4 crates.

Depender (with downloads and own rev deps)			mwc_util version
	2	mwc_core		^5.3.3
	2	mwc_keychain		^5.3.3
	1	mwc_store		^5.3.3
		mwc_chain		^5.3.3