3.0.0 RC3

• Stylesheets are now written in SCSS. The compiled files will remain in git, as there is no straightforward build process for Drupal modules yet.
• The [table] tag plugin is much more robust and powerful now. Instead of tabulating the rendered HTML content (which easily breaks nesting), the element now only processes delimiters in the top-level text content of the tag, ensuring that contained HTML elements remain intact.
• Unquoted attribute values can no longer begin with an unescaped dangling quote. (This avoids regex backtracking.)
• HTML linebreaks are now applied to text elements in the BBCode tree, rather than the output. This avoids rendering linebreaks that were added by Twig templates.
• More tests and refactoring.