Ionic serve: File(s) changes not reflected in the browser, slows down development

Ionic serve isn't serving the latest changes after saving a file. It's kind of a deal breaker during/for development. I am often forced to save a file at least once or restart ionic serve in order to work around this annoying issue.

**Steps to reproduce:**
1. Unpack https://drive.google.com/file/d/0B4eB_Qz7OSaTVndrVC1TdlliSkE/view?usp=sharing
2. Yarn (or npm install)
3. ionic serve
4. Make some small edit in src/components/bar/bar.html

The same issue is present even when using ionic CLI 2.2.3

global packages:

@ionic/cli-utils : 1.1.2
Ionic CLI : 3.1.2

local packages:

@ionic/app-scripts : 1.3.7
@ionic/cli-plugin-ionic-angular : 1.1.2
Ionic Framework : ionic-angular 3.2.1

System:

Node : v6.10.3
OS : macOS Sierra
Xcode : Xcode 8.3.2 Build version 8E2002
ios-deploy : 1.9.1
ios-sim : 5.0.13

使用提供的專案執行 yarn 或 npm install，接著執行 ionic serve 並編輯 src/components/bar/bar.html，以重現問題。追蹤 CLI 的檔案監看與重新載入路徑；當儲存的編輯內容無需額外儲存或重新啟動 ionic serve 就能反映在瀏覽器中時，即表示完成。

由索引模型根據 Issue 內容生成。