Remove CSS and JS tokenizers + related sniffs

[gsherwood]

Maintaining these tokenizers takes time, and they are not able to parse modern CSS and JS anyway, so they are pretty much useless. It's time to remove them.

[seriquynh]

I absolutely agree. The modern software world contains various tools to check CSS and JS styles. PHP_CodeSniffer should focus on the right thing - the PHP programming language.

[GaryJones]

Is there a ballpark date for when 4.0.0 is expected to drop? Months? Years?

[gsherwood]

Is there a ballpark date for when 4.0.0 is expected to drop? Months? Years?

It's not years away, but it wont be this year. After 3.5.0 is released (hopefully in a few weeks) I'll get started on a 4.0 branch to begin the changes.

Even after 4.0 is release, I'll still support version 3 for a while with bug fixes and critical changes. How long depends on how many there are, but I try not to drop support until the bug reports for an old version basically stop coming in.

[gsherwood]

I've now removed the tokenizers + all non-PHP checks inside sniffs + all JS/CSS test files + changed the ---extensions CLI arg to not allow passing a tokenizer.