Fix PHP 7.3 deprecations in lib/ directory (Part 1).

[syntaxseed]

Have begun fixing PHP 7.3->7.4 deprecations for the project. Began with lib/ directory.

Fixed:

• Curly brace syntax for accessing array elements and string offsets has been deprecated in PHP 7.4.
• Passing the $glue and $pieces parameters in reverse order to join has been deprecated since PHP 7.4; $glue should be the first parameter and $pieces the second.

I will continue this work in future PRs. Just making sure this is wanted. :)

Using PHPCS:

phpcs --standard=PHPCompatibility --extensions=php,inc,lib --runtime-set testVersion 7.3- . 

[phy25]

My apologies but I have done something here:
https://github.com/splitbrain/dokuwiki/tree/fix-tests-php74

Not opening a new PR for this yet because we are waiting for #2850 (and after this get merged a lot of PRs needs to be rebased in order to get the tests working).

[splitbrain]

@phy25 I'm unsure about the status here. Does your branch replace this PR? I'd be happy to have this (or something based on this) merged.

[syntaxseed]

I can rebase if needed.

Was planning to do more along these lines, if it's ok.

[phy25]

My branch, notably 439cabd, is a superset of this one. I guess we can merge this one first and I can rebase mine.

[syntaxseed]

@phy25 sounds good!

[phy25]

I finally have some time to look into this. This (and mine) needs to be worked again from the beginning because of massive conflicts.

I will keep this open and delete my commits regarding this.

[syntaxseed]

@phy25 Ok so want me to rebase this and start again?

[phy25]

@syntaxseed Yes you are welcome to do so.

[syntaxseed]

Please bear with me as this is my first large rebase on a forked project. I think I have rebased successfully onto the latest from master and updated my PR.

[phy25]

LGTM.