Todo: PHPCS 2.9.0: adjust some register() functions

[jrfnl]

I've pulled a PR upstream in PHPCS which has just been merged, which will add a new PHP_CodeSniffer_Tokens::$textStringTokens array.

In contrast to the PHP_CodeSniffer_Tokens::$stringTokens array - which contains the tokens for typical PHP string variables, this new array will contain also include T_INLINE_HTML, T_HEREDOC and T_NOWDOC.

Up to now, we often would use PHP_CodeSniffer_Tokens::$stringTokens and add the other three for sniffs examining text, now this can be replaced by using PHP_CodeSniffer_Tokens::$textStringTokens instead.

These adjustments should only be pulled/merged when:

• PHPCS has released version 2.8.2 (or whatever else the next version will be called) 2.9.0
• WPCS has upped the minimum requirement to PHPCS 2.8.2 2.9.0
• TRTCS has merged the "current" (future) version of WPCS containing the above change back in

[jrfnl]

I've prepared the PR for this: https://github.com/WPTRT/WordPress-Coding-Standards/tree/feature/issue-128-use-new-token-array

As we need to wait for the next PHPCS release and WPCS upgrading, this PR can not be pulled yet.

When ready, newly merged sniffs (merged between now and when the prerequisites for this PR have been met) will need to be reviewed & potentially adjusted for the same.