Android Studio: Files to exclude for Subversion
http://dimitar.me/android-studio-what-files-and-directories-to-exclude-when-importing-into-subversion-or-git/
ExpandableListView
http://www.journaldev.com/9942/android-expandablelistview-example-tutorial
Requesting Permissions at Run Time
https://developer.android.com/training/permissions/requesting.html