GUI for --disable-wallet compiles and -disablewallet mode

There is not much in the GUI to be done without wallet,
though it's possible to change options, watch the sync process,
and use the debug console.

So embed the debug console in the main window.

src/qt/optionsmodel.cpp

@@ -14,8 +14,10 @@
 #include "init.h"
 #include "main.h"
 #include "net.h"
+#ifdef ENABLE_WALLET
 #include "wallet.h"
 #include "walletdb.h"
+#endif
 
 #include <QSettings>
 #include <QStringList>
@@ -67,8 +69,10 @@ void OptionsModel::Init()
     // by command-line and show this in the UI.
 
     // Main
+#ifdef ENABLE_WALLET
     if (!settings.contains("nTransactionFee"))
         settings.setValue("nTransactionFee", 0);
+#endif
 
     if (!settings.contains("nDatabaseCache"))
         settings.setValue("nDatabaseCache", 25);
@@ -137,6 +141,7 @@ void OptionsModel::Upgrade()
 
     settings.setValue("bImportFinished", true);
 
+#ifdef ENABLE_WALLET
     // Move settings from old wallet.dat (if any):
     CWalletDB walletdb(strWalletFile);
 
@@ -181,6 +186,7 @@ void OptionsModel::Upgrade()
             walletdb.EraseSetting("addrProxy");
         }
     }
+#endif
 
     Init();
 }
@@ -227,6 +233,7 @@ QVariant OptionsModel::data(const QModelIndex & index, int role) const
         case ProxySocksVersion:
             return settings.value("nSocksVersion", 5);
 
+#ifdef ENABLE_WALLET
         case Fee:
             // Attention: Init() is called before nTransactionFee is set in AppInit2()!
             // To ensure we can change the fee on-the-fly update our QSetting when
@@ -236,6 +243,7 @@ QVariant OptionsModel::data(const QModelIndex & index, int role) const
             // Todo: Consider to revert back to use just nTransactionFee here, if we don't want
             // -paytxfee to update our QSettings!
             return settings.value("nTransactionFee");
+#endif
         case DisplayUnit:
             return nDisplayUnit;
         case DisplayAddresses:
@@ -318,13 +326,14 @@ bool OptionsModel::setData(const QModelIndex & index, const QVariant & value, in
             }
         }
         break;
-
+#ifdef ENABLE_WALLET
         case Fee: // core option - can be changed on-the-fly
             // Todo: Add is valid check  and warn via message, if not
             nTransactionFee = value.toLongLong();
             settings.setValue("nTransactionFee", (qint64)nTransactionFee);
             emit transactionFeeChanged(nTransactionFee);
             break;
+#endif
         case DisplayUnit:
             nDisplayUnit = value.toInt();
             settings.setValue("nDisplayUnit", nDisplayUnit);