CoubDownloader 3.7

The latest release cycle focused on accessibility.

The following points summarize the most important changes.

Additions:

-) basic GUI powered by Gooey
-) support for config files
-) custom FFmpeg path
-) replacing disallowed characters in filename

Technical changes:

-) basic checks for default options
-) overhauled get_name()
-) improved archive handling
-) various renamed options

Fixes:

-) ominous error messages for failed certificate verification
-) trying to catch aiohttp-related errors if only urllib is available