Fixing long-standing scrolling-text spaces by rewriting node-ffmpeg module behavior

EFV uses the nodejs plugin fluent-ffmpeg, whose author has provided little maintenance. Some implementations no longer follow current coding standards. For a long time, scrolling text could not contain spaces, and burning ass or srt subtitles failed when filenames contained spaces. Rather than waiting for updates, I modified its core code to resolve spaces completely.

Updates

• One: Rewrote part of fluent-ffmpeg for greater stability.
• Two: Scrolling text now supports spaces, ASCII : and ’.
• Three: Fixed burning matching ass or srt subtitle files when filenames contain spaces.

This exclusive EFV update resolves the various space-related issues.