新的类与接口

## New Classes and Interfaces ### [Intl](http://php.net/manual/en/book.intl.php) * [IntlChar](http://php.net/manual/en/class.intlchar.php) ### [Reflection](http://php.net/manual/en/book.reflection.php) * [ReflectionGenerator](http://php.net/manual/en/class.reflectiongenerator.php) * [ReflectionType](http://php.net/manual/en/class.reflectiontype.php) ### [Session Handling](http://php.net/manual/en/book.session.php) * SessionUpdateTimestampHandlerInterface ### Exception Hierarchy * [Throwable](http://php.net/manual/en/class.throwable.php) * [Error](http://php.net/manual/en/class.error.php) * [TypeError](http://php.net/manual/en/class.typeerror.php) * [ParseError](http://php.net/manual/en/class.parseerror.php) * [AssertionError](http://php.net/manual/en/class.assertionerror.php) * [ArithmeticError](http://php.net/manual/en/class.arithmeticerror.php) * [DivisionByZeroError](http://php.net/manual/en/class.divisionbyzeroerror.php)