QT代码补全

QCompleter用法参考如下链接：

http://blog.youkuaiyun.com/taiyang1987912/article/details/35287023

http://blog.youkuaiyun.com/hai200501019/article/details/8455808

http://blog.youkuaiyun.com/taiyang1987912/article/details/50541458

其他实现方法：

http://www.cppblog.com/biao/archive/2009/10/31/99873.html

http://blog.youkuaiyun.com/starcloud_zxt/article/details/5186489