Tests FileMapping

Test mappingEntryForURL
    http://www.example.com -> null
    http://www.example.com/ -> /home/example.com/
    http://localhost/index.html -> /var/www/
    http://localhost/foo/index.html -> /var/www/
    https://localhost -> null
    http://example.com -> null
Test mappingEntryForPath
    /home/example.com -> null
    /home/example.com/ -> http://www.example.com/
    /var/www/index.html -> http://localhost/
    /var/www/foo/index.html -> http://localhost/