add maven-bundle-plugin configuration

The configuration has been added, so we could a manual manifest
generation. The generated manifest could be used by developers to
identify missing imports.
The manifest generation could be triggered by:
mvn bundle:manifest -DniceManifest=true
The "nice manifest" option will e.g. add line breaks after every
imported package.
Now you can have a look at the manifest that would be generated by the
bndtool using:
cat target/classes/META-INF/MANIFEST.MF

Signed-off-by: Markus Rathgeb <maggu2810@gmail.com>