qt: Add option to (not) spend unconfirmed change

- Add a wallet tab to options dialog
- Move fee setting to wallet tab
- Add new setting to set -nospendzeroconfchange from UI

src/qt/optionsdialog.cpp

@@ -148,11 +148,14 @@ void OptionsDialog::setModel(OptionsModel *model)
 void OptionsDialog::setMapper()
 {
     /* Main */
-    mapper->addMapping(ui->transactionFee, OptionsModel::Fee);
     mapper->addMapping(ui->bitcoinAtStartup, OptionsModel::StartAtStartup);
     mapper->addMapping(ui->threadsScriptVerif, OptionsModel::ThreadsScriptVerif);
     mapper->addMapping(ui->databaseCache, OptionsModel::DatabaseCache);
 
+    /* Wallet */
+    mapper->addMapping(ui->transactionFee, OptionsModel::Fee);
+    mapper->addMapping(ui->spendZeroConfChange, OptionsModel::SpendZeroConfChange);
+
     /* Network */
     mapper->addMapping(ui->mapPortUpnp, OptionsModel::MapPortUPnP);