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/Serializer.h

@@ -106,6 +106,7 @@ public:
     int addZeros (size_t uBytes);
 
     int addVL (Blob const& vector);
+    int addVL (Slice const& slice);
     int addVL (const void* ptr, int len);
 
     // disassemble functions