android 4.0 SDK 原生的contacts， 通讯录管理，对于想了解android 通讯录实现的人来说是个很好的例子。结构有点复杂，看起来稍微有些费力-android 4.0 SDK native contacts, address book management, is a good example for those who want to learn android contacts to achieve. The structure is a bit complicated,