functest: Build Docker images with jjb

functest: Build Docker images with jjb

docker-build: Dependency & manifest support

Except for images that have dependencies (as functest-components,
functest-helthcheck, functest-restapi, functest-features,
functest-smoke, functest-vnf), all docker images
are built SEQUENTIALLY in a multijob Phase called 'build-base-img'.
The images with dependencies are built in PARALLEL in the second
Phase, called 'build-child-img', only if the first Phase result is
SUCCESFULL.
The manifest images are created in a third Phase,
'create-img-manifest', through opnfv-manifest.sh script, only if
Phase 'build-child-img' result is SUCCESFULL.

To create manifest images, a mandatory step is to preinstall
manifest-tool on the build image dedicated VM (arm and/or amd)

JIRA: ARMBAND-310

Change-Id: Iaa6640568ed18a3b087db56449173841dd2757ff
Signed-off-by: Delia Popescu <delia.popescu@enea.com>
Signed-off-by: Fatih Degirmenci <fatih.degirmenci@ericsson.com>