studio-引入外来包

参考: http://stackoverflow.com/questions/16588064/how-do-i-add-a-library-project-to-the-android-studio

举例：
库： https://github.com/AltBeacon/android-beacon-library.git
主工程: https://github.com/AltBeacon/android-beacon-library-reference.git

1. File->Import Project:先导入android-beacon-library-reference工程
2. File->Import Module:导入android-beacon-library作为module,module名为:android-beacon-library

3. 这个时候gradle文件sync是不成功的。因为默认会在主工程目录下寻找android-beacon-library目录，找不到。所以要在setting.gradle里加上

   project(':android-beacon-library').projectDir = new File('../android-beacon-library')

4. setting.gradle里包含新的库

   include ':app', ':android-beacon-library'

5. android-beacon-library-reference的app模块下的build.gradle把引用aar改为引用工程

   dependencies {
       compile project(':android-beacon-library')
      //compile 'org.altbeacon:android-beacon-library:2+@aar'
   }

https://bitbucket.org/fangj/altbeacon-example