Modifications to support line numbers within CSS

[sidkshatriya]

As discussed in #78 (comment)

The canonical validator points out issues in the CSS on the exact line of the HTML document. In our case the line number we provide is the line number of the containing <style> tag. To provide exact line number within the CSS we might need to make changes to the the PHP parser library ( https://packagist.org/packages/sabberworm/php-css-parser ).

So we need to make two changes:

• Make changes to our fork ( https://github.com/Lullabot/PHP-CSS-Parser) of sabberworm/php-css-parser to support line numbers. (This could later be submitted as a pull request upstream; but composer allows us to point to our repo if we need to also)
• Make changes to our amp-library code to support validation error line numbers within the CSS

[sidkshatriya]

You may track the sabberworm/php-css-parser related changes in https://github.com/Lullabot/PHP-CSS-Parser/tree/line-number-support-in-css-objects

PR #80 should be run only in conjunction with the above branch.

[sidkshatriya]

Added a pull request to the sabberworm/php-css-parser project MyIntervals/PHP-CSS-Parser#105

[sidkshatriya]

Made a huge amount of progress on MyIntervals/PHP-CSS-Parser#105

See the PR for changes. Hopefully it should not take too long to get this change accepted into mainline

[sidkshatriya]

The sabberworm PR was merged to master

[sidkshatriya]

With:

• Merge of PR 79 line numbers css issues #80
• Merge of our Add line number support in the sabberworm CSS parser MyIntervals/PHP-CSS-Parser#105 and subsequent release of 8.0.0

This ticket can be now closed.