Here are refinements requested by Belen to the project config variable page.

1) The 'not set' should have the muted class applied, so that it looks in
the nice, faded, grey colour

2) When you add a custom variable, the icon-trash is a bit too close to the
variable name. If you add the following line to the default.css file ...

dt > .icon-trash { padding-left: 5px; }

... it looks much better

3) * The ³DISTRO² value now has dynamic error checking for spaces and empty string.

So the check for the empty string is not really needed. The 'save' button
is disabled whenever the text field is empty, which prevents people from
trying to save an empty value. This is a behaviour we have implemented all
across Toaster. I think we should keep the same approach here: rely on the
disables state of the 'save' button and remove the empty string message.

The check for spaces works wonderfully, but it needs a bit of space from
the text field. If you move the <span> with id distro-error-message
outside the <div> with class input-append the whole thing works out a bit
better visually.

4) We should block duplicate custom variables that only differ by upper/lower case, just as we do for reserved variables