[change]change STORE_PATH  to /mnt/sdcard/snowdream/android/downloader/
[Update] 1.   compile 'com.github.snowdream.android.util.concurrent:multithread:0.0.7'
2.    compile 'com.github.snowdream.android.util:log:1.0.4'
[Update]  update gradle scripts
[Fixed] can not get the right filename automatically.
[Update] apk url
[Fixed] if exit the activity,the sql operation can not be executed.