upgrade.php css-layout fixes

Signed-off-by: illori illori@simplemachines.org
upgrade.php css-layout changes from antes

Signed-off-by: illori illori@simplemachines.org
a few more css/layout changes for upgrade.php

Signed-off-by: illori illori@simplemachines.org
final changes, progress bar to match install.php

Signed-off-by: illori illori@simplemachines.org
Merge pull request #494 from illori/upgrade.php-css-layout-fixes

upgrade.php css-layout fixes