* Those patch enable salt-(minion|master|api) services
    daemon auto-restart, in case any unclear exit will be
    detected. Systemd will try to run service each 3sec,
    till _StartLimitBurst_ limit will not be reached.
    (default 5)
  * Migrate systemd_minion_override.conf file
  * Duplicate patch for minion in base.sls and in service.sls

Change-Id: I65f35f1c50935af5692b740bb75ba0a629b18c48
Closes-Bug: PROD-23969 (PROD:23969)

salt-minion started via upstart is not using /etc/environment to
source variables therefore is not using system wide http_proxy parameters if
they are set there. With this patch if salt.minion.env_vars is set to engine:
file salt will set envvars in /etc/default/salt-minion and will use them for
all commands executed remotely via salt. Since /etc/default is not used on
systems with systemd override for salt-minion to use /etc/environmnet will be
set.

Change-Id: Icfe122de2486a83820a0bd2e2aeea4be3796c6aa
Closes-bug: PROD-16676