rosie go: improve new suite wizard behaviour.

This gives a larger, maximizable window for editing the
suite info data (access-list, title, etc). It also makes
sure that the project metadata is correctly loaded for
extra compulsory variable addition, and that changes
in the edit window do not persist when going back
and changing the project.

The metadata for our standard rose-suite.info options has
also been improved.

@arjclark, please review.
It's better style, technically, so I left it in - it added from an `import sys` I was
using for debugging.