[j2 parsing] Adopt new generate_config features

[j2 parsing] Adopt new generate_config features

- bump Pharos git submodule for j2 'do' extension + batch mode;
- adopt j2 'do' in our templates;
- use int filter for 'native' vlan check;
- lib.sh: adopt `-i` to remove `ln` hack for net_map.j2;
- lib.sh: adopt `-b` to speedup template parsing;

NOTE: Bumping Pharos will also bring in the latest changes in
pod_config.yml.j2, which include massive IP shifts and updates.

JIRA: FUEL-335

Change-Id: I7d3a997b3d8659d5f09f867870fb3a148c1ec6df
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>