make dialog a friend and add missing copyright notice

Author: jamaa

source/Dialogs/SettingsDialog.vb

@@ -1,6 +1,26 @@
+'BlueM.Wave
+'Copyright (C) BlueM Dev Group
+'<https://www.bluemodel.org>
+'
+'This program is free software: you can redistribute it and/or modify
+'it under the terms of the GNU Lesser General Public License as published by
+'the Free Software Foundation, either version 3 of the License, or
+'(at your option) any later version.
+'
+'This program is distributed in the hope that it will be useful,
+'but WITHOUT ANY WARRANTY; without even the implied warranty of
+'MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+'GNU Lesser General Public License for more details.
+'
+'You should have received a copy of the GNU Lesser General Public License
+'along with this program.  If not, see <https://www.gnu.org/licenses/>.
+'
 Imports System.Windows.Forms
 
-Public Class SettingsDialog
+''' <summary>
+''' Dialog for user settings
+''' </summary>
+Friend Class SettingsDialog
 
     Private isLoading As Boolean = True