Updated installation and update guides for 7.8-ee

Updated installation and update guides for 7.8-ee

This is not quite complete, it needs a merge from CE into EE after gitlab/gitlabhq!1531 is merged.

See merge request !315

Rebase MR project default value to false

See merge request !314

Merge CE into EE

See merge request !313

Conflicts:
	README.md
	app/assets/javascripts/project.js.coffee
	app/models/concerns/mentionable.rb
	app/models/project.rb
	app/models/project_services/jira_service.rb
	app/models/service.rb
	app/models/user.rb
	app/services/git_push_service.rb
	config/initializers/1_settings.rb
	config/routes.rb
	db/schema.rb
	doc/integration/README.md
	doc/integration/external-issue-tracker.md
	doc/integration/github.md
	spec/controllers/import/github_controller_spec.rb
	spec/helpers/merge_requests_helper.rb
	spec/lib/gitlab/upgrader_spec.rb
	spec/models/note_spec.rb
	spec/requests/api/groups_spec.rb
	spec/services/git_push_service_spec.rb

Rephrasing in documentation for manual installs

Rephrased the wording in the documentation to say "installation from source" or similar.

/cc @sytse

See merge request !1526

Rephrased wording in the documentation to say "installation from source" instead of  "manual installation" or similar.

Only send "Account was created for you" email when created by admin.

See #1985

cc @sytse

See merge request !1517

Add links to the quick help list

Add links in the quick help list to the pricing and feature comparison pages on about.gitlab.com.  See #1969

cc @sytse

See merge request !1525

Conflicts:
	db/schema.rb

Fix wrong word in document of google oauth

Modify the quick help list to add links to the pricing and feature
comparison pages of about.gitlab.com.

Jira integration doc and reference comment changes

See merge request !310

Update omniauth integration documentation

See merge request !1522

Sidebar tooltips

Show nice tooltips when hover on collapsed sidebar

See merge request !1521

Gitlab.com importer: Doc && screenshots

See merge request !1520

Allow users that signed up via OAuth to set their password in order to use Git over HTTP(S)

See #1982.

![Screen Shot 2015-02-13 at 13.37.28](https://dev.gitlab.org/uploads/gitlab/gitlabhq/69fe527252/Screen_Shot_2015-02-13_at_13.37.28.png)

There's a similar tooltip for SSH: "Add an SSH key to your profile to pull or push via SSH". These are always shown on-hover, even if the persistent flash above was hidden.

cc @sytse

See merge request !1512

Prevent autogenerated OAuth username to clash with existing namespace.

If the OAuth username already exists as a group rather than a user, automatic account creation would still fail.

See merge request !1511

Log documentation

See merge request !1513

Oauth2 provider doc

See merge request !1519

Test settings for issue tracker service

This adds minimum logging and response when using "test settings" button when the service is enabled.

See merge request !1506