Fixes #6942,bz1122924 - subscription reindex

Reindex subscriptions as part of product creation and destruction.
Merge pull request #4532 from dustint-rh/subs_list_not_reindexing

Fixes #6942,bz1122924 - subscription reindex
refs #6370 - automatically associate OS's with templates
Fixes #6287: Remove V1 API entirely.

This commit removes the existence of the V1 API by moving some controllers
to pure V2 API controllers and removing other, unused API controllers
and their corresponding tests.
Merge pull request #4547 from stbenjam/6370

refs #6370 - automatically associate OS's with templates
Merge pull request #4630 from ehelms/fixes-6287

Fixes #6287: Remove V1 API entirely.
Fixes #4121: Removes unused configuration values.

Since turning Katello into a Foreman plugin, some configuration values
have become unused. These unused configuration options have resulted
from either no longer being the server, functionality moving into
Foreman or the removal of headpin fencing.