v6616

There's a new command called Filter Documents.

It filters tabs (also works in other modes) that are likely documents, like pdf.

Right now it checks these extensions:

App.document_exts = [
  `pdf`, `djvu`, `xps`, `txt`, `md`,
  `csv`, `epub`, `mobi`, `azw3`, `azw4`,
  `fb2`, `cbz`, `cbr`, `doc`, `docx`,
  `rtf`, `odt`, `pages`, `xls`, `xlsx`,
  `ods`, `numbers`, `ppt`, `pptx`, `odp`, `key`,
]

So you can quickly find the books you're reading.

You can test it with this: http://cq-cq.eu/DJ5IL_rt007.pdf