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

Fix image url for emoji.

State machine 3

Improve network graph

Refer to virtual machine from the installation document.

Corrected some typos in gitlab.yml.example comments