initial changes to support RHEL
Merge remote-tracking branch 'garrypolley/COOK-3785-rhel-for-supervisor' into develop

Conflicts:
	providers/service.rb
Raise an exception if the platform is not supported.
Merge branch 'cook-3811-unsupported-platform' into develop

Conflicts:
	recipes/default.rb
[COOK-3785] updated to include link to init script.
Add centos and amazon to redhat platform block.
Merge remote-tracking branch 'garrypolley/COOK-3785-rhel-for-supervisor' into develop
DRY up supervisord.init template for redhat, centos, and amazon.
Fix up attribution.
Improve error handling if platform not supported.
Tweak rhel init script: add echo statement and change default return value.
Merge branch 'cook-3811-unsupported-platform' into develop
Fix exit status of "/etc/init.d/supervisord status" under rhel.

Prior to this change, under CentOS for example, the service[supervisord]
resource could think that supervisord was running even when it wasn't.
This is because under CentOS (and possibly other platforms), "supervisorctl
status" exits with status 0 even when supervisord is not running:

    $ supervisorctl status
    unix:///var/run/supervisor.sock no such file
    $ echo $?
    0
Make sure total_sleep is initialized.
Allow the template source to be customized.
DRY up enabling the supervisord service.
[COOK-3785] updated to include link to init script.
Moved building the supervisord.conf template last

It triggers the 'reload' action, which fails because init
files haven't been created yet. (on a fresh installation)
Reload supervisor if conf template changes.
Add centos and amazon to redhat platform block.