Cross-app interaction if android-ngn-stack is used

```
What steps will reproduce the problem?
1. Install Imsdroid and any other app that uses android-ngn-stack (i.e. Indoona)
2. Register both apps on their network
3. Trying to unregister the other app from the network.

What is the expected output? What do you see instead?
Imsdroid should stay connected to its network, an unregistration is notified
instead (red icon).

What version of the product are you using? On what operating system?
Latest version of Imsdroid. Any Android O.S. version

Please provide any additional information below.
In android-ngn-stack every broadcast intent message is called like
org.doubango.ngn.. and this is the same for every app that uses
android-ngn-stack. So every app that uses android-ngn-stack is listening for
the same set of broadcast intents.
A possible solution could be to add a configurable prefix to every broadcast
intent name so every app can set a proper one, making intent's names different
from app to app.

```

Original issue reported on code.google.com by `massimo....@gmail.com` on 23 Sep 2013 at 9:17