Several changes included...

- Suppress RuntimeException reported in the issue 2145361
-- Ask the parent Activity to show messages.
- Make vCard exporter a separated Activity.
-- There's no need to do this any more, but looks cleaner and easier to
   understand the behavior.
- Make error messages from vCard composer translatable.
- Stop using showDialog() when it is not appropriate.
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 68751db..546238a 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -419,5 +419,7 @@
         <activity android:name=".ImportVCardActivity"
             android:theme="@style/BackgroundOnly" />
 
+        <activity android:name=".ExportVCardActivity"
+            android:theme="@style/BackgroundOnly" />
     </application>
 </manifest>