When a new user confirm his email the signin tab is correctly shown.

# Conflicts:
#	app/controllers/admin/users_controller.rb
#	app/controllers/confirmations_controller.rb
#	app/controllers/profiles/emails_controller.rb
#	app/models/user.rb
#	app/services/emails/base_service.rb
#	app/services/emails/destroy_service.rb
#	app/views/devise/mailer/confirmation_instructions.html.haml
#	lib/api/users.rb
#	spec/services/emails/destroy_service_spec.rb

Improved file logging for authentication events

See merge request gitlab-org/gitlab-ce!9196

# This is the 1st commit message:
Add logging for all web authentication events

# This is the commit message #2:

Re-add underscore to after_inactive_sign_up_path_for

# This is the commit message #3:

Standardize on username=

# This is the commit message #4:

after_filter -> after_action, _resource -> resource

# This is the commit message #5:

Add two-factor login failures and account lockouts

# This is the commit message #6:

Move logging from two-factor concern to user model

# This is the commit message #7:

Add spaces around default parameter assignments

# This is the commit message #8:

Move logs out of user model

# This is the commit message #9:

Replace filtered_params with user_params

# This is the commit message #10:

Standardize case

# This is the commit message #1:

Fixes for username and AppLogger.info