requirements_details_url - display it under notice, not instead

[slaFFik]

Display a message with the link under notices (where all error are displayed), and not instead.

[slaFFik]

I think, it's better to give an option - under or instead. requirements_details_position - instead or under.

[tivnet]

Probably, can do it as a part of not_valid_actions. What to do:

• list OK's (only if Failures exist also, of course, or if DEBUG?)
• list Failures
• show a link
• deactivate