Added the escape hotkey, refined BoundingBox a bit

LobbyMenu also searches for a server as soon as you enter, so you don't
have to press an extra button, a good feature.

client/scenes/options_menu.cpp

@@ -92,7 +92,11 @@ void OptionsMenu::MouseButtonUp(SDL_MouseButtonEvent const& button) {
 }
 
 void OptionsMenu::KeyDown(SDL_KeyboardEvent const& key) {
-	//
+	switch(key.keysym.sym) {
+		case SDLK_ESCAPE:
+			SetNextScene(SceneList::MAINMENU);
+		break;
+	}
 }
 
 void OptionsMenu::KeyUp(SDL_KeyboardEvent const& key) {