create ec_secret serializer and serializer namespace
update commands
add multiply-secrets tests.
rename ec-tweak-add to ec-add, add tests for ec-add and ec-multiply
coments
Add address and base58 serializers.
Aply address and base58 serializers.
Add ripemd160 serializer and integrate with addr-encode/decode and update tests.
rename encode/decode-addr to addr-encode/decode.
Generalize use of serializers.