Add tsx load option, first tiled compat commit

MainWindow.cpp

@@ -464,10 +464,20 @@ void MainWindow::on_actionOpen_triggered() {
       this, tr("Open Project"), "",
       tr("All supported formats (*.egm *.yyp *.project.gmx *.gm81 *.gmk *.gm6 *.gmd);;GameMaker: Studio 2 Projects "
          "(*.yyp);;GameMaker: Studio Projects (*.project.gmx);;Classic "
-         "GameMaker Files (*.gm81 *.gmk *.gm6 *.gmd);;All Files (*)"));
+         "GameMaker Files (*.gm81 *.gmk *.gm6 *.gmd);;"
+         "Tiled Tileset (*.tsx);;All Files (*)"));
   if (!fileName.isEmpty()) openFile(fileName);
 }
 
+void MainWindow::on_actionSave_triggered() {
+  const QString &filter = "EGM (*.egm)";
+  const QString &fileName = QFileDialog::getSaveFileName(this, tr("Save Project"), "", filter);
+
+  if(!fileName.isEmpty()) {
+    egm::WriteProject(_project.get(), fileName.toStdString());
+  }
+}
+
 void MainWindow::on_actionPreferences_triggered() {
   PreferencesDialog preferencesDialog(this);
   preferencesDialog.exec();

MainWindow.h

@@ -61,6 +61,7 @@ class MainWindow : public QMainWindow {
   void on_actionNew_triggered();
   void on_actionOpen_triggered();
   void on_actionClearRecentMenu_triggered();
+  void on_actionSave_triggered();
   void on_actionPreferences_triggered();
   void on_actionExit_triggered();