Additional Admin APIs

Allow connection to Redis via unix socket

Refactor README to split production/development environments

Allow connection to Redis via unix socket, using
unix:/var/run/redis/redis.sock for example.

Default behaviour does not change, except that the full Redis URL must
be configured, with redis:// for tcp or unix: for unix socket.

Use secure protocol

Added methods to manage project deploy keys via API

Added methods to manage system hooks from API

Update README with references to versions.

Fix routing error

It should fix #2598.

It is linked to #2598.

default gitlab.relative_url_root to ENV['RAILS_RELATIVE_URL_ROOT']

Update doc/install/databases.md

Merge branch 'omniauth_no_email_1' of https://github.com/gliptak/gitlabhq into gliptak-omniauth_no_email_1

Conflicts:
	app/observers/user_observer.rb
	spec/observers/user_observer_spec.rb

fix: grouping commits by date desc doesn't sort the groups too