Fixed problem with extension chage

1. Extension is now correctly changed to .zip
Added ApkManager.GetApkManifest method

1. Added ApkManager class that will provide different APK specific
methods.
2. Added ApkManifest and ApkManifestRecord classes to the data model.
They represent an APK manifest (MANIFEST.MF) and a single record in it.
2. Added ApkManager.GetApkManifest() method that returns manifest file
(as ApkManifest) for the specified APK.
Added -test command

1. Added -test command to the command line configuration file. It allows
you to run any command you need to test.