Ulozto-downloader

* Added --enfoce-tor option
* Use cloudscraper to overcome Cloudflare CAPTCHA checks

* Fix of Tor port selection

* Support for downloading password protected files (--password option or by prompt during download)
* JSON frontend (selectable by --frontend option)
* Refactoring (LinkCache, TorRunner)

* Enhance output dir parameter functionality

* Use separate temp file directory for .udown, .ucache and Tor files
* Set by `--temp` option in cmd.py, default to current working directory
* Auto remove .udown and .ucache files on successful download using cmd.py
* Support for batch sequential download (multiple URLs could be
specified) when using cmd.py
* Enhanced cmd.py usage message
* TorRunner is not stopped inside Downloader class (caller responsibility)