docs(*): Document a lot more symbols that are missing comments in our generated docs.

modules/angular2/src/http/backends/browser_xhr.ts

@@ -1,6 +1,10 @@
 import {Injectable} from 'angular2/core';
 
-// Make sure not to evaluate this in a non-browser environment!
+/**
+ * A backend for http that uses the `XMLHttpRequest` browser API.
+ *
+ * Take care not to evaluate this in non-browser contexts.
+ */
 @Injectable()
 export class BrowserXhr {
   constructor() {}

modules/angular2/src/http/backends/jsonp_backend.ts

@@ -12,10 +12,29 @@ import {Observable} from 'rxjs/Observable';
 const JSONP_ERR_NO_CALLBACK = 'JSONP injected script did not invoke callback.';
 const JSONP_ERR_WRONG_METHOD = 'JSONP requests must use GET request method.';
 
+/**
+ * Abstract base class for an in-flight JSONP request.
+ */
 export abstract class JSONPConnection implements Connection {
+  /**
+   * The {@link ReadyState} of this request.
+   */
   readyState: ReadyState;
+
+  /**
+   * The outgoing HTTP request.
+   */
   request: Request;
+
+  /**
+   * An observable that completes with the response, when the request is finished.
+   */
   response: Observable<Response>;
+
+  /**
+   * Callback called when the JSONP request completes, to notify the application
+   * of the new data.
+   */
   abstract finished(data?: any): void;
 }
 
@@ -111,6 +130,9 @@ export class JSONPConnection_ extends JSONPConnection {
   }
 }
 
+/**
+ * A {@link ConnectionBackend} that uses the JSONP strategy of making requests.
+ */
 export abstract class JSONPBackend extends ConnectionBackend {}
 
 @Injectable()

modules/angular2/src/http/http.ts

@@ -35,7 +35,7 @@ function mergeOptions(defaultOpts, providedOpts, method, url): RequestOptions {
  * Performs http requests using `XMLHttpRequest` as the default backend.
  *
  * `Http` is available as an injectable class, with methods to perform http requests. Calling
- * `request` returns an {@link Observable} which will emit a single {@link Response} when a
+ * `request` returns an `Observable` which will emit a single {@link Response} when a
  * response is received.
  *
  * ### Example