Add reverse lookup provider "Das Telefonbuch" (DE).

Change-Id: Ic3b5197bb7d6d2955ada9f3d902decff088433ec
Cleanup some CAF code.

Instead of exposing the concept of supplementary service notifications
to InCallUI (and then not using it), convert the respective
notifications into boolean flags.

Change-Id: I0b72c3efdccb4aa163e27fb0205b939c32d7a184
Add missing space.

Change-Id: Ibd4b648012dd473468598355b5a58f7309102bd4
Fix FDN validity check UX.

Use a text watcher to enable/disable the save button instead of showing
a toast that the save button should not be used at that point.

Change-Id: Iaf5f9c9e7a53b3184bb1423d45f80948bfc8ebe0