[Plugin: WP Super Cache] Allow tighter permissions

Right now, WP Super Cache doesn’t let you change your settings unless wp-content is writable by the web server. However, the only files it needs to change are wp-content/wp-cache-config.php and the contents of wp-content/cache.

The plugin should allow you to change settings based on those permissions, rather than requiring all of wp-content to be writable (which, IMO, is a security risk).