Add a few missing classes.

These still need to be added to runtime/index.ts I'm working on how to derive the IDs.

https://github.com/captbaritone/webamp/pull/855

modern/src/runtime/FeedWatcher.ts

@@ -0,0 +1,29 @@
+import MakiObject from "./MakiObject";
+import * as Utils from "../utils";
+
+export default class FeedWatcher extends MakiObject {
+  /**
+   * getClassName()
+   *
+   * Returns the class name for the object.
+   * @ret The class name.
+   */
+  getclassname() {
+    return "FeedWatcher";
+  }
+
+  setfeed(feed_id: string) {
+    Utils.unimplementedWarning("setfeed");
+    return;
+  }
+
+  releasefeed() {
+    Utils.unimplementedWarning("releasefeed");
+    return;
+  }
+
+  onfeedchange(new_feeddata: string) {
+    Utils.unimplementedWarning("onfeedchange");
+    return;
+  }
+}

modern/src/runtime/Form.ts

@@ -0,0 +1,34 @@
+import GuiObject from "./GuiObject";
+import * as Utils from "../utils";
+
+export default class Form extends GuiObject {
+  /**
+   * getClassName()
+   *
+   * Returns the class name for the object.
+   * @ret The class name.
+   */
+  getclassname() {
+    return "Form";
+  }
+
+  getcontentsheight() {
+    Utils.unimplementedWarning("getcontentsheight");
+    return;
+  }
+
+  newcell(groupname: string) {
+    Utils.unimplementedWarning("newcell");
+    return;
+  }
+
+  nextrow() {
+    Utils.unimplementedWarning("nextrow");
+    return;
+  }
+
+  deleteall() {
+    Utils.unimplementedWarning("deleteall");
+    return;
+  }
+}

modern/src/runtime/PlDir.ts

@@ -0,0 +1,19 @@
+import MakiObject from "./MakiObject";
+import * as Utils from "../utils";
+
+export default class PlDir extends MakiObject {
+  /**
+   * getClassName()
+   *
+   * Returns the class name for the object.
+   * @ret The class name.
+   */
+  getclassname() {
+    return "PlDir";
+  }
+
+  showcurrentlyplayingentry() {
+    Utils.unimplementedWarning("showcurrentlyplayingentry");
+    return;
+  }
+}