Merge branch 'sync-email-from-omniauth' into 'master'

app/controllers/profiles_controller.rb

app/helpers/profiles_helper.rb

app/views/profiles/show.html.haml

changelogs/unreleased/sync-email-from-omniauth.yml

config/gitlab.yml.example

config/initializers/1_settings.rb

...170531202042_rename_users_ldap_email_to_external_email.rb

db/migrate/20170603200744_add_email_provider_to_users.rb

...migrate/20170531203055_cleanup_users_ldap_email_rename.rb

db/schema.rb

lib/gitlab/ldap/user.rb

lib/gitlab/o_auth/user.rb

spec/controllers/profiles_controller_spec.rb

spec/helpers/profiles_helper_spec.rb

spec/lib/gitlab/ldap/user_spec.rb

spec/lib/gitlab/o_auth/user_spec.rb