Merge branch '13691-allow-admin-to-reset-user-password-and-force-password-reset-on-next-login' into 'master'

Force password change after admin reset

Closes #13691.

See merge request !4016

Added authentication service for docker registry

This adds a simple authentication service for docker which uses current user credentials to authenticate pulls and pushes.

I have only one concern. Since the `.docker/config` is unencrypted, thus the password for user stored there is unencrypted, maybe we should from the start implement function to generate/provide a separate password just for the purposes of accessing docker registry?

What do you think @jacobvosmaer @sytses @marin?

cc @marin 

See merge request !3787

When an admin changes a user's password for them, force the user to
reset the password after logging in by expiring the new password
immediately.

Add cache count metrics to rails cache

See merge request !4157

Change colors for charcoal and graphite sidebar themes
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

cc @skyruler @jschatz1 

See merge request !4149

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Refactor diff notes

Related to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4101

/cc @rspeicher 

See merge request !4110

# Conflicts:
#	config/initializers/1_settings.rb