Add file version to activity stream

Signed-off-by: tobiasKaminsky <tobias@kaminsky.me>

src/main/java/com/owncloud/android/ui/fragment/FileDetailActivitiesFragment.java

@@ -26,8 +26,10 @@ import android.accounts.AuthenticatorException;
 import android.accounts.OperationCanceledException;
 import android.content.Context;
 import android.graphics.PorterDuff;
+import android.os.AsyncTask;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.design.widget.Snackbar;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentActivity;
 import android.support.v4.widget.SwipeRefreshLayout;
@@ -389,4 +391,4 @@ public class FileDetailActivitiesFragment extends Fragment implements ActivityLi
     public void onRestoreClicked(FileVersion fileVersion) {
         operationsHelper.restoreFileVersion(fileVersion, userId);
     }
-}
+}

src/main/java/com/owncloud/android/utils/BitmapUtils.java

@@ -34,6 +34,7 @@ import com.owncloud.android.lib.common.utils.Log_OC;
 
 import org.apache.commons.codec.binary.Hex;
 
+import java.io.UnsupportedEncodingException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.Locale;