Also changed expiration date to show "Never" instead of unix epoch in the pasta list, and renamed a few variables in animalnumbers.rs to make the function more readable.
- added cli param to change threads used by server
- added cli param hide html header and/or footer
- added cli param to remove css styling
- added cli param to set http basic auth username and optionally password for the server
- file pastas now delete the files from the disk as well when they expire
- index.html extended with form input
- pasta.html and pastalist.html show link to /file/{pasta.id}/{filename} path
- files are saved in pasta_data folder
- all data is now stored in pasta_data/database.json
- changed pastalist.html date format to exclude year
- added custom 404 error handler
