Fix: Do not pass null to function that expects DateTime or string (#869)

Enhancement: Enable `array_syntax` fixer

Co-authored-by: MathiasReker <mathias@reker.dk>

Closes GH-659.

Enhancement: Enable `indentation_type` fixer

Closes GH-622.

Swap uses of _SERVER[DOCUMENT_ROOT] for __DIR__

1/n - Update / and /include/ only.

Remove PHP 5.6 support note as it is no longer supported.

Don't show recently EOLed branches in the supported versions table.

Changed the behaviour of get_active_branches() so that callers can
choose whether to get recently EOLed branches or no

Don't show recently EOLed branches in the supported versions table.

Changed the behaviour of get_active_branches() so that callers can
choose whether to get recently EOLed branches or not. (This is basically
for the supported versions page; the other callers -- namely the front
page download links and bug tracker backend -- likely still want the
previous behaviour.)

After all, it's a little weird listing 5.5 as a supported version in the
table when we just made a big deal of EOLing it!

show more ...

Add a quick note about why 5.6 support is now longer.

Make the supported versions table a little more mobile friendly.

Colour code the branches on the supported version SVG.

Add a draft supported versions page, as suggested on Internals.