common.IsHex makes no sense

[stevenroose]

here

func IsHex(str string) bool {
	l := len(str)
	return l >= 4 && l%2 == 0 && str[0:2] == "0x"
}

This means that 0xHELLO_MY_NAME_IS_STEVEN_@#$^&* is valid hex, but 0102030f is not...