Use (int) instead of intval() for performance reasons and to unify it.

Micro-optimization (no its not nano^^) of int/float casting.
(int) is about 3 times faster than the method call. Same for (float).

And we already mainly use (int), (float) casts etc where applicable.

I used my auto-correct [Cast sniff](https://github.com/dereuromark/cakephp-codesniffer/blob/master/Vendor/PHP/CodeSniffer/Standards/MyCakePHP/Sniffs/PHP/CastSniff.php)

    cake CodeSniffer.CodeSniffer run --sniffs MyCakePHP.PHP.Cast {corefolder} -v -f

That means, we could make this a CakePHP code-sniffer rule to keep the improvement in the future.

It should be noted that I skipped on non-trivial replacements (more than a single argument) for now due to  probably errors then (`intval($x + $y)` would need to keep the parentheses). It would be easy to keep the additional (superfluous) parentheses, if no-one minds though. That would probably eliminate the change of errors.

// Inspired by [this](https://github.com/briannesbitt/Carbon/pull/169) and [this](http://hakre.wordpress.com/2010/05/13/php-casting-vs-intval/).