Allow add a condition telling the table to avoid ambiguity error.
Merge pull request #2504 from thiagotalma/master

Allow add a condition telling the table to avoid ambiguity error.
Fixes #2392: Added `addCssStyle()`, `removeCssStyle()`, `cssStyleFromArray()` and `cssStyleToArray()` to `Html`
Merge branch 'master' of git://github.com/yiisoft/yii2