[JeanC]

feb 16

- Added function to upload books

- Upload books, this will ask for the name of the map you want and create it if it does not exist. You can upload multiple books at once.
It will also ask if you want to make a collection with the name of that map if that does not yet exist and add the books.
- you can now also delete complete collections by pressing delete on a collection name, you are asked if you want to delete books as well.

ps, I don't even need to restart the kobo after modifying things, collections and books just show up, do remember to safely remove hardware though.

Edit: it's offline for now, i want to do a bit more testing.
Edit: it's online again, i did some thorough testing, everything works fine.
Also added a dialog screen for uploading.