TYPO3 Core

When using the config.concatenateJs = 1 option, the ResourceCompressor is loosing tag attributes such as the async attribute in the concatenateJsFiles method.
A fix would be to add 'async' => $fileOptions['async'] after line 201, but I guess, it's too dirty for the core?! What if one file should be loaded via async and another not?

Aside: Fresh installation with just tiny template:

config {
    concatenateJs = 1
}

page = PAGE
page.10 = TEXT
page.10.value = HELLO WORLD!
page.includeJSFooter {
    combined = path/to/file.js
    combined.async = 1
}

Maybe it would be possible to take care of async or defer.

This would be very flexible if only those file are concatenated with the same options

It would be great for Google Pagespeed

Patch set 2 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/57130

Patch set 3 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/57130

Patch set 4 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/57130

Patch set 5 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/57130

Patch set 6 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/57130