CatVec

CatVec is used at run time in 18 crates. It is a direct run-time dependency in 5 crates.

Depender (with downloads and own rev deps)			CatVec version
330	6	themelio-stf		^0.1.6
120	1	melodeon		^0.1.2
	8	melvm		^0.1.6
	2	melstf		^0.1.6
	1	mil	dev	^0.1.6