STWebViewController

Description:

1. add the progressView from "NJKWebViewProgress"

2. add the webView layout from "SVWebViewController"

3. add the gesture like "weixin" which can remove back by the pan gesture, and show with the screenshot

TODO List:

1. add the tag when the webView start load. When the webView load other web like "baidu.com" which can't load the "UIWebViewNavigationTypeLinkClicked" method.

2. It should add the webCache what can let the webView go back faster.