1125334 - Adds celery_t policy to constrain pulp_workers, pulp_resource_manager, and pulp_celerybeat

This introduces a new selinux policy named pulp-celery which defines the celery_t label. The policy has been tested on EL6 and EL7 with sync+publish, bind/unbind, update, register/unregister, pulp-admin upload, and node functionality.

The spec file is reworked to deploy and remove both the pulp-celery policy in addition to the pulp-server policy. I've cleaned up the bash scripts also.

The EL7 environment needed a few policy statements that did not compile on the EL6 environment, so the selinux policy is adjusted just before compilation depending on the platform. EL7 gets some additional statements. You'll see this addition in the pulp.spec file.

I've deleted pulp-selinux.py which has no chance of working without much effort, and removed it from the developer docs. This selinux policy will not work with a dev setup, only with an RPM based layout.

It also updates the release notes for 2.5.0, and adds a note about the selinux changes.

I looked at the foreman selinux policy, and its clearly grouped and documented which is great. This policy has a ways to go before it gets to that maturity, but seeing a thorough example is great.

Regarding the miscfiles_manage_cert_dirs(celery_t), I don't have the AVC denials on hand, but if this is concerning I think a BZ should be opened specifically to investigate this. If you want you could file the pulp bug.