Added VTN Coordinator to Karaf distribution.

This patch created a directory called externalapps in Karaf
distribution, and put VTN Coordiantor in it.

Change-Id: I76d7f5bb3831be4b75d921743ab024cbf43e7d86
Signed-off-by: Hideyuki Tai <Hideyuki.Tai@necam.com>
Merge "Added VTN Coordinator to Karaf distribution."