Replace gitlab-git-http-server with gitlab-workhorse

This MR keeps backwards compatibility in gitlab.rb.

See merge request !528

Added postgresql replication settings

This will add settings for enabling streaming replication in postgresql, default master.

WAL will be enabled by default so it's easier to add a slave to your current postgresql instance.

See merge request !532

Support the shared.path gitlab.yml setting



See merge request !530

Update cacerts to 2015.10.28 3c58c3f2435598a942dc37cdb02a3ec3



See merge request !529

Execute sysctl immediately.

Fixes #897 



See merge request !525

Fix deadlink to docs for GitLab Mattermost SSO

Just fix a deadlink to docs for GitLab Mattermost SSO.

cf. The changes appeared in [mattermost/platform@341d270](https://github.com/mattermost/platform/commit/341d270c2d8b750556d9735a9a8edd8b6fab2530)

See merge request !526

Move RPi building to extra stage to speed-up builds and fix docker tagging

/cc @rspeicher @marin 


See merge request !524

Create a file for each sysctl config and reload settings if they change.

Fixes #861 

See merge request !522

Added Amazon SES SMTP configuration example

Added simple Amazon SES configuration example for SMTP gitlab.rb settings

See merge request !508

Update Chef to 12.5.1

Upgrading Chef to 12.5.1 for 'Chef.event_handler'.  

This would allow us to run Chef handlers when certain events happen during a 'reconfigure' run.  Upgrading to 12.5 also means that we don't need to include and ship the 'chef_handler' cookbook, which provides some (but not all) of the functionality from this upgrade.

@marin - any chance you could take a look at this?

See merge request !520

Add a note about not removing the satellite path from the package for a while.



See merge request !521

Set svlogd prefix for mailroom

This is needed for usable UDP log shipping (syslog).

See merge request !519

Render omnibus-specific mailroom.yml

And turn off mailroom quiet mode.

See merge request !518

And turn off mailroom quiet mode.

Fix configuration and documentation of Mattermost feedback email

* FeedbackName and FeedbackEmail settings are now in the generated configuration
* Correct documentation for ConnectionSecurity setting

I did not add a Changelog entry since I wasn't sure whether it would go under 8.2.0 or 8.1.x

See merge request !517