Test cross-domain CSS loading

Mozilla Bug 524223

##

1. text/css
   1. same origin
      1. valid
      2. malformed
      3. http error
   2. cross origin
      1. valid
      2. malformed
      3. http error
   3. same to cross
      1. valid
      2. malformed
      3. http error
   4. cross to same
      1. valid
      2. malformed
      3. http error
2. text/html
   1. same origin
      1. valid
      2. malformed
      3. http error
   2. cross origin
      1. valid
      2. malformed
      3. http error
   3. same to cross
      1. valid
      2. malformed
      3. http error
   4. cross to same
      1. valid
      2. malformed
      3. http error

## Quirks

## Standards