CWallet class

* A new class CKeyStore manages private keys, and script.cpp depends on access to CKeyStore.
* A new class CWallet extends CKeyStore, and contains all former wallet-specific globals; CWallet depends on script.cpp, not the other way around.
* Wallet-specific functions in CTransaction/CTxIn/CTxOut (GetDebit, GetCredit, GetChange, IsMine, IsFromMe), are moved to CWallet, taking their former 'this' argument as an explicit parameter
* CWalletTx objects know which CWallet they belong to, for convenience, so they have their own direct (and caching) GetDebit/... functions.
* Some code was moved from CWalletDB to CWallet, such as handling of reserve keys.
* Main.cpp keeps a set of all 'registered' wallets, which should be informed about updates to the block chain, and does not have any notion about any 'main' wallet. Function in main.cpp that require a wallet (such as GenerateCoins), take an explicit CWallet* argument.
* The actual CWallet instance used by the application is defined in init.cpp as "CWallet* pwalletMain". rpc.cpp and ui.cpp use this variable.
* Functions in main.cpp and db.cpp that are not used by other modules are marked static.
* The code for handling the 'submitorder' message is removed, as it not really compatible with the idea that a node is independent from the wallet(s) connected to it, and obsolete anyway.

src/keystore.cpp

@@ -12,7 +12,7 @@
 // mapKeys
 //
 
-std::vector<unsigned char> GenerateNewKey()
+std::vector<unsigned char> CKeyStore::GenerateNewKey()
 {
     RandAddSeedPerfmon();
     CKey key;
@@ -22,12 +22,12 @@ std::vector<unsigned char> GenerateNewKey()
     return key.GetPubKey();
 }
 
-bool AddKey(const CKey& key)
+bool CKeyStore::AddKey(const CKey& key)
 {
     CRITICAL_BLOCK(cs_mapKeys)
     {
         mapKeys[key.GetPubKey()] = key.GetPrivKey();
         mapPubKeys[Hash160(key.GetPubKey())] = key.GetPubKey();
     }
-    return CWalletDB().WriteKey(key.GetPubKey(), key.GetPrivKey());
 }
+