简单的浏览图片，用QT实现，初学者代码(Very good code, translated from: http://www.cnblogs.com/craigtao/p/6640470.html
When working on a project, record some small function modules. This is a module that needs to be written when developing video platform (local image browsing)
Technical points needed:
1. File filtering (support for fuzzy search), with Qt built-in regular
2. Image loading display
3. Signals and slots
The image's fuzzy search list and display image are respectively packaged into their respective widget classes
Direct code:)