Add SSH custom port support for install/installation.md
Update doc/install/structure.md
Updated CHANGELOG
Merge pull request #2632 from yin8086/SSHPort

Add SSH custom port support for install/installation.md
Update custom SSH connection section in installation guide
Eliminate horizontal shifting on diff body heights
Add a warning prompt to the setup task
Remove the setup task from the maintenance docs
Rename gitlab:app:setup task to gitlab:setup
switch to use link_to_member to prevent 500 if user is a project owner but does not have membership and leave comment
Merge pull request #2649 from tjeezy/patch-1

Eliminate horizontal shifting on diff body heights
Merge pull request #2650 from riyad/setup-task-warning

Improve setup task, by making it less dangerous
Improve link to comment targets on dashboard