The solution is as follows:
- Copy the files over from your working environment (or do an export from your source control tool) into a new folder on NearlyFreeSpeech.net (NFS.net). Let's call the new folder "abc".
- Import your database into NFS.net.
- Configure database settings as necessary on the NFS.net version of the site.
- Add the abc folder and everything in it to the web group.
- Go into the .htaccess file in /home/public/abc and add "RewriteBase /abc" under "RewriteEngine on".
- Add "RewriteBase /abc/app" to the .htaccess in /home/public/abc/app and add "RewriteBase /abc/app/webroot" to the one in /home/public/abc/app/webroot.