Fixes #14264 - improve primary interface selection

(cherry picked from commit 308f611d9bb17173588a6f59c7a914b551923a7b)

Fixes #13984 - inherit subnet from hostgroup even for image-based provisioning

(cherry picked from commit 17f4ee612bf1308cb51d4644bdd76ba7dc73eea7)

Fixes #12936 - Host inherits attributes when hostgroup is AR object

(cherry picked from commit d7110d54ad51a85eadde8283606e88cf01de8b19)

fixes #13883 - replace :order association option with block

Already deprecated in an earlier Rails release, :order in an
association should be replaced by a scope block calling order().

(cherry picked from commit 3d2098bd472851ce4d030ff78adc30044eaa7d3b)

Fixes #13834 - associate puppet proxies only for puppet imports

(cherry picked from commit 6f16c9159dad61641908d88eeb62ab45d22bd396)

Fixes #13664 - rescue smtp errors if mail failed on host built

Fixes #6342 - merge compute profile when attributes in api host#create

API v2 host#craete call now merges user specified compute attributes
with compute profile. UI functionality remains untouched.

fixes #12791 - allow access to boot_files_uri and medium in safe_mode

Fixes #13557 - Rubocop enforce specifying a timezone

Rubocop can enforce what timezone to store in the database ,
so we can ensure everything is stored using UTC and we don't
miss these things in code reviews. When objects are displayed,
they must use the time provided by set_timezone in the...

fixes #13440 - rename Host#model_name to #hardware_model_name

Rails 4.2 defines a model_name instance method which is used in routing
and called from link_to. Rename our model_name methods to
hardware_model_name to prevent this overlapping and causing link_to...