Increase sdk from 20 to 21. Previously, increasing sdk and support libraries version from 20 to 21 caused menu (action bar) with add run to disappear.

To fix this and simplify project, increase minSdkVersion from 9 to 11. Remove support libraries that were mainly supporting api < 11.
Currently approximately 90% of Android devices run sdk >= 11.
http://developer.android.com/about/dashboards/index.html