Replace _disposables with Disposable, add jsdoc

src/common/Lifecycle.ts

@@ -5,18 +5,29 @@
 
 import { IDisposable } from 'xterm';
 
+/**
+ * A base class that can be extended to provide convenience methods for managing the lifecycle of an
+ * object and its components.
+ */
 export abstract class Disposable implements IDisposable {
   protected _disposables: IDisposable[] = [];
 
   constructor() {
   }
 
+  /**
+   * Disposes the object, triggering the `dispose` method on all registered IDisposables.
+   */
   public dispose(): void {
     this._disposables.forEach(d => d.dispose());
     this._disposables.length = 0;
   }
 
-  public register<T extends IDisposable>(t: T): void {
-    this._disposables.push(t);
+  /**
+   * Registers a disposable object.
+   * @param d The disposable to register.
+   */
+  public register<T extends IDisposable>(d: T): void {
+    this._disposables.push(d);
   }
 }