Remove RippleAddress:

The RippleAddress class was used to represent a number of fundamentally
different types: account public keys, account secret keys, node public
keys, node secret keys, seeds and generators.

The class is replaced by the following types:
* PublicKey for account and node public keys
* SecretKey for account and node private keys
* Generator for generating secp256k1 accounts
* Seed for account, node and generator seeds

src/ripple/protocol/impl/Serializer.cpp

@@ -242,6 +242,14 @@ int Serializer::addVL (Blob const& vector)
     return ret;
 }
 
+int Serializer::addVL (Slice const& slice)
+{
+    int ret = addEncoded (slice.size());
+    if (slice.size())
+        addRaw (slice.data(), slice.size());
+    return ret;
+}
+
 int Serializer::addVL (const void* ptr, int len)
 {
     int ret = addEncoded (len);