Added filemtime to merged JS/CSS hash calculation algorithm

[boesbo]

Description (*)

Add the timestamp of the files in the MD5 HASH generation criteria of the files.

Fixed Issues (if relevant)

1. Fixes Improving the file name generation logic for JS and CSS files #4003

Questions or comments

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All automated tests passed successfully (all builds are green)
• Add yourself to contributors list

[boesbo]

If you can I ask you for a review @fballiano

[boesbo]

@fballiano I improved the PR. There was some confusion with the variable name, so your question was legitimate. I have made the code clearer and accepted your suggestion not to run filemtime() several times;

[fballiano]

@boesbo great, I'll test it out a bit

[fballiano]

I don't like the way merging works by default in OM, but that's another topic, I've tested this PR and it does what it claims and I think it's ok to merge

[boesbo]

Non mi piace il modo in cui funziona l'unione per impostazione predefinita in OM, ma questo è un altro argomento, ho testato questo PR e fa quello che afferma e penso che sia ok unire

It is only an improvement of the current functionality in view of a modern (now current) management of these assets in the browser cache. Thx!

[boesbo]

If you can I ask you for a review @kasper-agg

[fballiano]

I'll merge this in a couple of days if there's none against

[kasper-agg]

If you can I ask you for a review @kasper-agg

What @fballiano already mentioned, the whole merging thing is another topic, your PR fixes the current issue at hand 👍