ActionBarActivity is deprecated. You should use AppCompatActivity.
Please read v7 Support Libraries .I hope it will helps you .
Android Support Library package contains several libraries that can
  be included in your application. Each of these libraries supports a
  specific range of Android platform versions and set of features.
The important features and version support
  provided by the Support Libraries to help you decide which of them you
  should include in your application. In general, we recommend including
  the v7 support and v7 appcompat libraries, because they support a wide
  range of Android versions and provide APIs for recommended user
  interface patterns.
v7 Libraries
There are several libraries designed to be used with Android 2.1 (API
  level 7) and higher. These libraries provide specific feature sets and
  can be included in your application independently from each other.
v7 appcompat library
This library adds support for the Action Bar user interface design
  pattern.
android:versionCode
An integer value that represents the version of the application code,
  relative to other versions. The value is an integer so that other
  applications can programmatically evaluate it.
Courtesy goes to Difference between android-support-v7-appcompat and android-support-v4