Hug

- Improved cli output, to output nothing if None is returned

- Enabled `hug.types.multiple` to be exposed as nargs `*`
- Fixed a bug that caused a CLI argument when adding an argument starting with `help`
- Fixed a bug that caused CLI arguments that used `hug.types.multiple` to be parsed as nested lists

- Improved boolean type behavior on CLIs

- Fixes a bug that caused hug cli clients to occasionally incorrectly require additional arguments
- Added support for automatically converting non utf8 bytes to base64 during json output

- Added initial built-in support for video output formats (Thanks arpesenti!)
- Added built-in automatic support for range-requests when streaming files (such as videos)
- Output formatting functions are now called, even if a stream is returned.
- Input formatting functions now need to be responsible for dealing with text encoding and streaming
- Added additional default input format for `text/plain` and a few other common text based formats
- If no input format is available, but the body parameter is requested - the body stream is now returned
- Added support for a generic `file` output formatter that automatically determines the content type for the file

- Drastically improved hug performance when dealing with a large number of requests in wsgi mode