Typo
Json: error Invalid UTF-8 sequence is detectable since PHP 5.3.1, removed workaround
Json: added support for future error messages
Json: own error handler is required only in PHP < 5.5
removed obsolete function_exists()
added marker interface Nette\Utils\IHtmlString for objects that will be not escaped by Latte. (BC break)

BC break: Nette\Templating\ITemplate is not escaped any more.