Cleanup NMR and features build

[Jean-Baptiste Onofré]

Hi all,

Starting with Karaf features plugin 2.1.3, it's not more required to 
have artifacts in the local repo before calling add-features-to-repo goal.
Now, the plugin is able to download the artifacts from maven 
repositories and add to the local repo.

In the NMR and Features assembly, we have a huge part of the POM only 
dedicated to the dependencies.

I propose (after the next NMR and Features releases) to cleanup the POM 
to remove the dependencies set.

WDYT ?

Regards
JB