Avoid loading the list of available previews in FLVPlayer and MP3Player viewers via XHR
  - Use thumbnailModification option on WebPreview instance if available
  - Detect the quickshare page and if we still do not know what has been pre-generated then just assume blindly that we can generate as needed (fixes #29)
Add srcMaxSize option to PdfJs viewer - fixes #16
Add border around selected page in the main view (fixes #3)