agree popup 추가

MainForm.cs

@@ -54,6 +54,19 @@ namespace friction
 			dockPanel.Font = new Font(dockPanel.Font.FontFamily, 12.0f);
 		}
 
+		private void MainForm_Shown(object sender, EventArgs e)
+		{
+			if (Config.GetInstance().DidAgreeAlert() == true)
+				return;
+
+			AlertPopup alert = new AlertPopup();
+			DialogResult alertResult = alert.ShowDialog();
+			if (alertResult == DialogResult.OK)
+				Config.GetInstance().SetAgreeAlert();
+			else
+				Application.Exit();
+		}
+
 		void UpdateRecentFile()
 		{
 			recentToolStripMenuItem.DropDownItems.Clear();