- Small syntax changes
- image_advanced:
  + show full size image after upload IF thumbnail is not available
  + prevent potential bug when insert duplicated files (`selection` previously not filtered)
  + prevent potential bug when new upload file with invalid type can be insert (still hidden, but inserted)
- file_advanced:
  + re-use multiple frames for each field to better control file types
  + prevent potential bug when insert duplicated files (`selection` previously not filtered)
  + prevent potential bug when new upload file with invalid type can be insert (still hidden, but inserted)
- file:
  + fix bug: new added file not shown