[Documentation] add prepare for update details to 5.1 to 6.0 guide

helps detect and correct issues that may occur during upgrade before
they have already occurred. easier to address issues before you start
upgrade process.

Feature ldap tests

Move specs to proper places. Relates to #154

This is already mergeable, will continue in a new branch for additions & refactorings.

See merge request !1053

Avoid ldap.allow_username_or_email_login issues

See merge request !1016

make CI build faster

Comment typo.

Comment typo.

Use svg instead of png to get better image quality

Fix Atom feed for comments

Return extra empty line in blob render

Updated the spring gem and fixed the guard file

Enable highlighting for blame

This method existed to allow LDAP users to take over existing GitLab
accounts if the part before the '@' of their LDAP email attribute
matched the username of an existing GitLab user. I propose to disable
this behavior in order to prevent unintended GitLab account takeovers.

After this change it is still possible to take over an existing GitLab
account with your LDAP credentials, as long as the GitLab account email
address matches the LDAP user email address.

The example LDAP configuration in gitlab.yml enables the
allow_username_or_email_login setting. Because the effect of this
setting is somewhat counterintuitive, I propose we make 'false' the
example default. The settings initializer already sets this setting to
'false'.

Don't allow edit of system notes

Fix #1412

See merge request !1052

Move cache setup to config/application.rb

See merge request !1050

Improve issue ui

Fix code overflow for description block

See merge request !1051

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

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

Visibility fix

Fixes #1529

See merge request !1049

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

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

Before this change we were trying to configure Rails.cache in an
initializer. It seems that by the time the initializers are loaded,
Rails.cache is already instantiated, so changing the settings does not
achieve anything anymore. This was causing Rails to default to a file
storage cache instead of the Redis cache, which in turn broke `rake
cache:clear`.

Fix XSS issue

When view blob as RAW make sure we allow only 2 kind of type: 'text/plain' and 'application/octet-stream'

Fixes #1514

See merge request !1045

Use a ? after the $request_uri to perform a valid Redirect while cloning...

[refactor] Remove HAML eval for const strings.

Fix overflow in 'my projects' list

Mask password in import URL while importing.