Perfmatters 2.3.6

* Fixed an issue that was causing excluded selectors to not be recongnized properly after Used CSS was cleared.
* Minor adjustments to the new plugin UI.

* Updated plugin settings UI.
* Added new post meta option to Clear Used CSS for an individual page or post type.
* Added new perfmatters_rucss_excluded_selectors filter.
* Fixed a lazy loading issue that was preventing some images from loading properly in Safari.
* Migrated Delay JS Timeout dropdown to a simpler on/off toggle that will default to 10 seconds. Our filter is also still available to set a custom timeout value.
* Fixed an issue with MU plugin that was interfering with rewrite rules in some instances.
* Added additional excluded page builder parameter for Flatsome UX.
* Moved restore default functionality to a separate option on the tools page.
* Code refactoring.
* Translation updates.

* Changed default setting for Used CSS Method from file to inline, as we think this will be the more compatible solution for most users going forward. If you were previously using the file method, you may need to save that option again.
* Added width and height parameters to placeholder SVGs to prevent warnings for a ratio mismatch that would happen for some images.
* Fixed an issue where the noscript tags were getting malformed for some images inside picture tags after lazy loading.
* Removed placeholder SVGs on source tags since the image tag will already have one.
* Changed settings export file name date format to be easier to organize when managing multiples.
* Updated tooltip for Blank Favicon option to be more clear.