Stubpce Update

Stubpce Update

(FakePCE implementation) This implementation is only for test purposes and allows
to load PCE topology from xml file.

This commit includes :
- Add java package 'org.opendaylight.transportpce.stubpce.topology'
which implements java classes for getting topology elements from xml
file and build path descriptions List.
- This file 'fakepce.xml' must be in src/main/resources to be loaded
in target/classes and must also follow 'SuperNode'
model (cf fakepce.xml).
- change 'leaf node-id' in case termination-point
in model yang transportpce-pathDescription by 'leaf tp-node-id'
to not interfere with 'leaf node-id' in case node.
- Add PathDescriptionList in stubpce yang model to stored
all possible paths in datastore.
- update servicehandler dependency
- move stubpce and stubrenderer to tests folder
- add dependency 'Version update to 1.6 of the service-path model'.

Change-Id: I29391cc098706c261d109f8f1860bbfd78012c69
Signed-off-by: Martial COULIBALY <martial.coulibaly@gfi.fr>
Signed-off-by: Olivier RENAIS <olivier.renais@orange.com>
(cherry picked from commit 730925ab6a616aef3cc2f5b8b190774fa5708407)