[TYPO3-core] RFC #15489: remove code warnings about XCLASS and naming annoyances

[Franz Holzinger]

Hello Dmitry,

> Marcus Krause wrote:
>> Warnings allow a TYPO3 admin to judge an extension's code quality based
>> on a first glance.
>
> Exactly! And "the code still works" is not an argument. The code may work
> but if it does not follow CGL, most likely it is badly written. So it is a
> reason to to use that code and search for a better alternative. At least
> this is my opinion :)

If an extension is based on XCLASS, then this is not a good solution. 
XCLASS will lead to errors because the original extension will not care 
about the derived extensions using the XLCASS. A good code will only 
base on a hook function.
Therefore XCLASS warnings should completely be removed.

> Some warnings are unavoidable but the less of them, the better.
The XCLASS warning is not important to anyone, not even to developers. 
The developer is able by himself to see if the PHP file has a hook 
function available. It should never happen that he is forced to build an 
extension based on a XCLASS.

- Franz