Fixed a warning with Maven regarding mismatched SDK target values

The target value in project.properties did not match that declared in AndroidManifest.xml, giving this warning with Maven in IntelliJ IDEA:

>Error when importing module '~apklib-com.actionbarsherlock_actionbarsherlock_4.3.0': Cannot find appropriate Android platform for API level 14

I realize this is happening because I don't have the files for API 14 installed, but this is still inconsistent with the target SDK value in the manifest of 16. Updating the value to android-16 stops this warning.