[docker] Switch to containerized Salt Master

[docker] Switch to containerized Salt Master

* Refactor OPNFV salt-formulas mechanism to resemble upstream git
  structure:
  - git submodules: add new submodule for each formula we patch;
  - create salt-formula-x directories for OPNFV formulas;
  - move mcp/metadata/service contents to their each formula subdir;
  - use `make patches-import` for patches previously handled by
    patch.sh;
  - retire patch.sh
* states: add virtual_init:
  - mostly based on old salt.sh, which is now obsolete;
  - exclude salt-master service restart (it would kill the container);
* scenarios: cleanup (rm cfg01 virtual node def), adopt virtual_init;
* reclass: align our model with prebuilt container's Salt config:
  - drop linux:network pillar data (handled by Docker);
  - stop applying linux.system state on cfg01;
  - align salt user homedir;
  - drop salt-formula packages (preprovisioned);
* minor plumbing in deploy.sh and lib.sh;

JIRA: FUEL-383

Change-Id: I28708a9b399d3f19012212c71966ebda9d6fc0ac
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>