Sunstone: Add setting to hide version number

[xBytez]

Description
For security, we'd like to not disclose the version information to the user/login page. I suggest adding a sunstone-server setting to be able to hide.

Use case
Just for security reasons we wish to not show version numbers (we do this for nginx too by using server_tokens off;.

Interface Changes
The interface would simply show "OpenNebula by OpenNebula Systems" rather than "OpenNebula 5.8.1 by OpenNebula Systems" if this setting is turned on.

Additional Context
I notice that the current version is also used when including some resources like JavaScript or stylesheets. We have to think of a good alternative (timestamp of some sorts?).

Progress Status

• Branch created
• Code committed to development branch
• Testing - QA
• Documentation
• Release notes - resolved issues, compatibility, known issues
• Code committed to upstream release/hotfix branches
• Documentation committed to upstream release/hotfix branches

[kvaps]

Now there is too many upgrades available 🙂

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. The OpenNebula Dev Team

[kvaps]

This change is still desirable