gui: MainWindow: Settings: Allow changing database path too

gui/mainwindow.cpp

@@ -363,12 +363,14 @@ void MainWindow::initSettingsTabs()
 	QString pdfViewerCmd = settings.value(SETTINGS_KEY_PDFVIEWER).toString();
 	QString excludedPaths = Common::excludedPaths().join(';');
 	QString mountPaths = Common::mountPaths().join(';');
+	QString databasePath = Common::databasePath();
 	int numPagesPerPreview = settings.value(SETTINGS_KEY_PREVIEWSPERPAGE, 20).toInt();
 
 	ui->txtSettingPdfPreviewerCmd->setText(pdfViewerCmd);
 	ui->txtSettingIgnoredPaths->setText(excludedPaths);
 	ui->txtSettingMountPaths->setText(mountPaths);
 	ui->spinSettingNumerPerPages->setValue(numPagesPerPreview);
+	ui->txtSettingDatabasePath->setText(databasePath);
 }
 
 void MainWindow::saveSettings()
@@ -378,11 +380,13 @@ void MainWindow::saveSettings()
 	QString pdfViewerCmd = ui->txtSettingPdfPreviewerCmd->text();
 	QStringList excludedPaths = ui->txtSettingIgnoredPaths->text().split(';');
 	QStringList mountPaths = ui->txtSettingMountPaths->text().split(';');
+	QString databasePath = ui->txtSettingDatabasePath->text();
 
 	settings.setValue(SETTINGS_KEY_PDFVIEWER, pdfViewerCmd);
 	settings.setValue(SETTINGS_KEY_EXCLUDEDPATHS, excludedPaths);
 	settings.setValue(SETTINGS_KEY_MOUNTPATHS, mountPaths);
 	settings.setValue(SETTINGS_KEY_PREVIEWSPERPAGE, ui->spinSettingNumerPerPages->value());
+	settings.setValue(SETTINGS_KEY_DBPATH, databasePath);
 
 	settings.sync();
 

gui/mainwindow.ui

@@ -406,6 +406,25 @@
           </layout>
          </widget>
         </item>
+        <item>
+         <widget class="QGroupBox" name="groupSettingDatabasePath">
+          <property name="title">
+           <string>Database path</string>
+          </property>
+          <layout class="QVBoxLayout" name="verticalLayout_10">
+           <item>
+            <widget class="QLabel" name="lblSettingDatabasePath">
+             <property name="text">
+              <string>Path of the database. Note: Changing it here will create an empty, new database. The old will not be moved.  </string>
+             </property>
+            </widget>
+           </item>
+           <item>
+            <widget class="QLineEdit" name="txtSettingDatabasePath"/>
+           </item>
+          </layout>
+         </widget>
+        </item>
         <item>
          <widget class="QGroupBox" name="Misc">
           <property name="title">