Merge pull request #144 from andschwa/nginx

Allow Nginx to be disabled
Added support for nginx domain aliases

This commit add new feature: gitlab_domain_alias, This feature
make it possible to also configure dns aliases for the nginx
server name.

I use this, because i need the server to be acessible by gitlab_domain
(git.example.com) and  git hostname without the domain.

The default behaviour is gitlab_domain_alias disabled (false), so this
would not break anyone that expect the old behaviour (only gitlab_domain)
in nginx server_name.

There is example on how to use this feature on init.pp and test coverage.

If you want to use gitlab_domain_alias just configure the parameter
Only one alias
This will create the following  nginx server_name:
class {'gitlab':
       gitlab_domain       => "git.example.com",
       gitlab_domain_alias => "git"
      }
Multiple aliases
This will create the following nginx server_name:
class {'gitlab':
       gitlab_domain       => "git.example.com",
       gitlab_domain_alias => "git gitlab gitlab.example.com"
      }

(Cherry-pick from commit 1f7fe246a00329262a6b270c54a883f222a48304)
Update changelog
Managing postfix conflict

This wouldn't seem necessary because of the use of ensure_packages, but
unfortunately it's not a perfect function and only works if everyone
uses it. The thias/postfix module declares the Postfix package with
different parameters, and should probably take priority for the
package. This simple flag disables this module's (already really light)
management of the Postfix package if need-be.
Merge branch 'master' into development
My bad, forgotten change fixed
Merge branch 'postfix' into development

Conflicts:
	manifests/init.pp
	manifests/params.pp
	manifests/setup.pp