tc-error

tc-error is used at run time in 8 crates.

Depender (with downloads and own rev deps)			tc-error version
	4	tc-btree		^0.4
	1	tc-math		^0.4
	3	tc-table		^0.4
	2	tc-tensor		^0.4
	5	tc-transact		^0.4
	6	tc-value		^0.4
	7	tcgeneric		^0.4.0
		tinychain		^0.4